Methods and compositions using calcium carbonate

ABSTRACT

Provided herein are compositions and methods including hydraulic cement, supplementary cementitious material, and/or self-cementing material. Methods for making the compositions and using the compositions are provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No.61/291,811, filed Dec. 31, 2009; U.S. Provisional Application No.61/360,829, filed Jul. 1, 2010; and U.S. Provisional Application No.61/371,606, filed Aug. 6, 2010, all of which are incorporated herein byreference in their entireties.

GOVERNMENT SUPPORT

Work described herein was made in whole or in part with Governmentsupport under Award Number: DE-FE0002472 awarded by the Department ofEnergy. The Government has certain rights in this invention.

BACKGROUND

Calcium carbonates are used in numerous industries from papermaking, toadhesives production, to construction. Calcium carbonates that areformed as a result of a carbon dioxide sequestering process can be usedin many of the aforementioned applications and in effect serve twopurposes: to sequester carbon dioxide and to function as a calciumcarbonate material. One area where this dual purpose is doublybeneficial to the environment is in construction materials, specificallycements and concretes. As the production of conventional cements is oneof the contributors to the emission of carbon dioxide into theatmosphere through the calcination of conventional cements as well asthe energy needed to heat the kilns, reductions in the amount ofconventional cements used can help to reduce the amount of carbondioxide in the earth's atmosphere.

SUMMARY

In one aspect, there is provided a self-cementing composition,comprising at least 1% w/w vaterite in saltwater, wherein thecomposition upon rinsing with fresh water, setting, and hardening has acompressive strength of at least 14 MPa. In one aspect, there isprovided a self-cementing composition, comprising 1% w/w to 99% w/wvaterite in saltwater, wherein the composition upon rinsing with freshwater, setting, and hardening has a compressive strength of at least 14MPa.

In some embodiments, the composition is oven dried at 40° C. whilesetting. In some embodiments, the composition is cured at 60° C. inhumid atmosphere after drying. In some embodiments, the composition isdewatered before rinsing with water.

In some embodiments, the composition upon combination with water,setting, and hardening has a compressive strength in a range of 14-35MPa or 20-40 MPa.

In some embodiments, the composition has a δ¹³C of between −12‰ to −25‰.In some embodiments, the composition has a δ¹³C of less than −20‰. Insome embodiments, the composition has a δ¹³C of less than −25‰.

In some embodiments, the vaterite is in a range of 1% w/w to 99% w/w. Insome embodiments, the vaterite is in a range of 40% w/w to 85% w/w. Insome embodiments, the vaterite is in a range of 47% w/w to 99% w/w. Insome embodiments, the composition further comprises ACC. In someembodiments, the vaterite is in a range of 10% w/w to 99% w/w and theACC is in a range of 1% w/w to 90% w/w. In some embodiments, thevaterite is at least 75% w/w. In some embodiments, the vaterite is atleast 90% w/w. In some embodiments, the vaterite is at least 95% w/w. Insome embodiments, the vaterite is at least 99% w/w. In some embodiments,the ACC is at least 5% w/w. In some embodiments, the ACC is 5%-30% w/w.

In some embodiments, the composition further comprises a polymorphselected from the group consisting of amorphous calcium carbonate,aragonite, calcite, ikaite, a precursor phase of vaterite, a precursorphase of aragonite, an intermediary phase that is less stable thancalcite, polymorphic forms in between these polymorphs, and combinationthereof. In some embodiments, the vaterite and the polymorph are in avaterite:polymorph ratio of 1:1 to 20:1. In some embodiments, thevaterite and the polymorph are in a vaterite:polymorph ratio of greaterthan 1:1, 2:1, 3:1, 4:1, or 5:1. In some embodiments, the vaterite andthe polymorph are in a vaterite:polymorph ratio of 9:1-20:1.

In some embodiments, the composition further comprises one or more ofpolymorph selected from the group consisting of aragonite, calcite, andikaite, wherein the aragonite, the calcite and/or the ikaite are presentin at least 1% w/w. In some embodiments, the composition furthercomprises at least 1% w/w aragonite or between 1% w/w to 80% w/waragonite. In some embodiments, the composition further comprises atleast 1% w/w calcite or between 1% w/w to 80% w/w calcite. In someembodiments, the composition further comprises 1% w/w to 25% w/wcalcite. In some embodiments, the composition further comprises at least1% w/w ikaite or between 1% w/w to 80% w/w ikaite. In some embodiments,the composition further comprises at least 1% w/w ACC or between 1% w/wto 90% w/w ACC and one or more of polymorph selected from the groupconsisting of aragonite, calcite, and ikaite, wherein the aragonite, thecalcite and/or the ikaite are present in at least 1% w/w or between 1%w/w to 80% w/w. In some embodiments, the composition further comprisesone or more of polymorph selected from the group consisting ofaragonite, calcite, ikaite, and combination thereof, wherein thearagonite, the calcite, the ikaite, or the combination thereof areindependently in a range between 1% w/w to 80% w/w. In some embodiments,the composition further comprises 1%-80% w/w aragonite and 1%-80% w/wcalcite.

In some embodiments, the composition further comprises strontium (Sr).In some embodiments, the Sr is present in an amount of 1-50,000 partsper million (ppm).

In some embodiments, the composition further comprises magnesium (Mg).In some embodiments, the Mg is present as a carbonate.

In some embodiments, the vaterite and the magnesium carbonate are in avaterite:magnesium carbonate ratio of greater than 1:1 or between1:1-500:1.

In some embodiments, the composition is a particulate composition withan average particle size of 0.1-100 microns. In some embodiments, thecomposition is a particulate composition with an average particle sizeof 1-50 microns. In some embodiments, the composition is a particulatecomposition with an average particle size of 1-10 microns.

In some embodiments, the composition has a bulk density of between 75lb/ft³-170 lb/ft³. In some embodiments, the composition has a bulkdensity of between 75 lb/ft³-125 lb/ft³.

In some embodiments, the composition has an average surface area of from0.5 m²/gm-50 m²/gm. In some embodiments, the composition has an averagesurface area of from 2 m²/gm-10 m²/gm.

In some embodiments, the composition further comprises nitrogen oxide,sulfur oxide, mercury, metal, derivative of any of nitrogen oxide,sulfur oxide, mercury, and/or metal, or combination thereof.

In some embodiments, the composition has a zeta potential of greaterthan −25 mV. In some embodiments, the composition has a zeta potentialof between −25 to 45 mV or between −25 to 10 mV. In some embodiments,the composition has a zeta potential in a range of −25 mV to 1 mV.

In some embodiments, a ratio of a calcium ion:carbonate ion in thecomposition is greater than 1:1. In some embodiments, a ratio of acalcium ion:carbonate ion in the composition is 1.5:1 or 2:1.

In some embodiments, the composition is synthetic. In some embodiments,the composition is non-naturally occurring. In some embodiments, thecomposition is in a powdered form. In some embodiments, the compositionis in a dry powdered form. In some embodiments, the composition isdisordered or is not in an ordered array.

In one aspect, there is provided a formed building material, comprisingthe above recited composition of the invention or the set and hardenedform thereof. In some embodiments, the building material is selectedfrom the group consisting of building, driveway, foundation, kitchenslab, furniture, pavement, road, bridges, motorway, overpass, parkingstructure, brick, block, wall, footing for a gate, fence, or pole, andcombination thereof. In one aspect, there is provided a formed buildingmaterial, comprising the above recited composition of the invention orthe set and hardened form thereof. In one aspect, there is provided anaggregate, comprising the above recited composition of the invention orthe set and hardened form thereof. In one aspect, there is provided apackage, comprising the above recited composition of the invention and apackaging material adapted to contain the composition.

In one aspect, there is provided a method for making the above recitedcomposition of the invention, comprising (a) contacting an alkalineearth-metal containing water with a CO₂ source; and (b) subjecting thealkaline earth-metal containing water of step (a) to one or moreconditions to make the above recited composition of the invention.

In some embodiments, the CO₂ source is an industrial waste streamcomprising flue gas from combustion; a flue gas from a chemicalprocessing plant; a flue gas from a plant that produces CO₂ as abyproduct; or combination thereof. In some embodiments, the alkalineearth-metal containing water is sea water, brine, or combinationthereof. In some embodiments, the one or more conditions comprise one ormore of precipitation and dewatering of the precipitate to make thecomposition. In some embodiments, the one or more conditions comprisecontacting the alkaline earth-metal containing water with a protonremoving agent. In some embodiments, the proton removing agent isselected from the group consisting of oxide, hydroxide, carbonate, coalash, naturally occurring mineral, and combination thereof. In someembodiments, the one or more conditions comprise subjecting the alkalineearth-metal containing water to electrochemical condition.

In one aspect, there is provided a composition made by the methoddescribed as above.

In one aspect, there is provided a system for making the above recitedcomposition of the invention, comprising (a) an input for an alkalineearth-metal containing water; (b) an input for a CO₂ source; and (c) areactor connected to the inputs of step (a) and step (b) that isconfigured to make the composition of the invention.

In one aspect, there is provided a method for making a cement productfrom the above recited composition of the invention, comprising (a)combining the composition of the invention with water under one or moresuitable conditions; and (b) allowing the composition to set and hardeninto a cement product.

In some embodiments, the one or more suitable conditions are selectedfrom the group consisting of dewatering, rinsing with water, setting,drying, curing, and combination thereof.

In some embodiments, the method further comprises transporting theproduct to a subterranean location.

In one aspect, there is provided a system for making a cement productfrom the above recited composition of the invention, comprising (a) aninput for the composition of the invention; (b) an input for water; and(c) a reactor connected to the inputs of step (a) and step (b)configured to mix the above recited composition of the invention withwater under one or more suitable conditions to make a cement product.

In one aspect, there is provided a method for making formed buildingmaterial from the above recited composition of the invention, comprising(a) combining the above recited composition of the invention with anaqueous medium under one or more suitable conditions; and (b) allowingthe composition to set and harden into the formed building material.

In some embodiments, the aqueous medium comprises fresh water. In someembodiments, the composition is poured into molds before or after step(a) of combination. In some embodiments, the mold is for the formedbuilding material.

INCORPORATION BY REFERENCE

All publications, patents, and patent applications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication, patent, or patent application wasspecifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIG. 1 illustrates a flow diagram of a precipitation process accordingto an embodiment of the invention.

FIG. 2 illustrates a schematic of a system according to some embodimentsof the invention.

FIG. 3 illustrates a Gibbs free energy diagram of the transition fromvaterite to aragonite and aragonite to calcite.

FIG. 4 illustrates a schematic of a system according to some embodimentsof the invention.

FIGS. 5A-F illustrate SEM images of nanoclusters of particles assemblinginto the vaterite spheres.

FIG. 6 illustrates transformation of vaterite into various morphologiesincluding aragonite bundles, aragonite needles, platelets and cubes.

FIGS. 7A-B illustrate precipitation of the polymorphs on vaterite. FIG.7A illustrates precipitation of calcite on the surface of vateritespheres. By the dissolution of the more soluble vaterite phase, hollowcalcite microspheres develop. FIG. 7B illustrates precipitation ofaragonite bundles on the surface of the continually hollowingmicrospheres.

FIG. 8 illustrates a schematic of the creation of hollow calcitemicrospheres and aragonite bundles.

FIG. 9 illustrates SEM images of the transformation of vaterite indeionized water at 4,000 times magnification.

FIGS. 10A-B illustrate an effect of temperature on the size of thecrystals. Heating can result in smaller calcite crystals. FIG. 10Aillustrates transformation of vaterite in NaCl solution at roomtemperature. FIG. 10B illustrates transformation of vaterite in NaClsolution at 110° C.

FIG. 11 illustrates framboidal vaterite formed by aggregation ofvaterite microcrystallites.

FIGS. 12A-B illustrate effect of sodium chloride on the transformationof vaterite into calcite.

FIGS. 13-18 illustrate the diffraction pattern of the crystals ofvaterite (FIG. 13-15), mixed carbonate phases (FIG. 16), and calcite(FIG. 17-18).

FIG. 19 illustrates a flow diagram for preparing the compositionaccording to some embodiments of the invention.

FIG. 20 illustrates a particle size distribution comparison for OPC(Ordinary Portland Cement) (small dots), fly ash (long dot) and RCM(reactive carbonate minerals) (solid).

FIG. 21 illustrates a dose response compressive strength graph for RCMwhen mixed with Portland cement.

FIG. 22 illustrates XRD results of several ACC samples, with scanresults similar to that seen in literature. The intensity of ACC5 isreflective of a different scan condition.

FIG. 23 illustrates XRD of sample created using protocol ACC4. Halite,calcite, and vaterite were present.

FIG. 24 illustrates ACC5, showing amorphous material when initiallyanalyzed. Subsequent analysis (4 days later) showed crystalline calcitewith small amounts of aragonite.

FIG. 25 illustrates blended ACC material analyzed over time. This sampleshowed long-term stability (˜1 and ½ years).

FIGS. 26A-C illustrate the SEM images of three compositions withdifferent dispersions and zeta potentials.

FIG. 27 illustrates the compressive strength of three compositions withdifferent zeta potentials.

FIG. 28 illustrates the cumulative heat of three compositions withdifferent zeta potentials.

FIG. 29 illustrates the stability of vaterite composition in the mothersupernate when made from seawater+CaCl₂ dihydrate+NaCl+25% wt Na₂CO₃.

FIGS. 30A-D illustrate the stability of vaterite composition when madefrom tap water+CaCl₂ dihydrate+0.25 M Na₂CO₃ (Ca:base stiochiometricratio of 1:1).

FIGS. 31A-D illustrate the stability of vaterite composition when madefrom tap water+CaCl₂ dihydrate+0.25 M Na₂CO₃ (Ca:base stiochiometricratio of 1.5:1).

FIGS. 32A-D illustrate the stability of vaterite composition when madefrom tap water+CaCl₂ dihydrate+0.25 M Na₂CO₃ (Ca:base stiochiometricratio of 2:1).

FIG. 33 illustrates the SEM image of the precipitated slurry of Example20.

FIG. 34 illustrates the compressive strength of the composition aftercuring for 7 days, 14 days, and 28 days.

DETAILED DESCRIPTION

This invention provides compositions, methods, and systems ofpolymorphs, such as amorphous calcium carbonate, vaterite, aragonite,calcite, and/or ikaite; methods and systems for making and using thecompositions; and the materials formed from such compositions, such asaggregates and formed or pre-formed building materials.

The compositions include hydraulic cement, supplementary cementitiousmaterial, or self-cementing compositions that include polymorph forms ofcalcium carbonate, such as, but not limited to, vaterite (CaCO₃) aloneor vaterite in combination with amorphous calcium carbonate(CaCO₃.nH₂O), aragonite (CaCO₃), calcite (CaCO₃), ikaite (CaCO₃.6H₂O), aprecursor phase of vaterite, a precursor phase of aragonite, anintermediary phase that is less stable than calcite, polymorphic formsin between these polymorphs, or combination thereof. Also providedherein are the formed building materials and aggregates that are madefrom these compositions. Further provided herein are methods of makingand using the hydraulic cements, supplementary cementitious material, orself-cementing compositions. Further provided herein are methods ofmaking cement products, such as, aggregates and pre-formed buildingmaterials from the hydraulic cement, supplementary cementitiousmaterial, or self-cementing compositions. The compositions find use in avariety of applications, including use in a variety of buildingmaterials and building applications.

Typically, Ordinary Portland Cement (OPC) is made primarily fromlimestone, certain clay minerals, and gypsum, in a high temperatureprocess that drives off carbon dioxide and chemically combines theprimary ingredients into new compounds. The energy required to fire themixture consumes about 4 GJ per ton of cement produced. Because thecarbon dioxide is generated by both the cement production processitself, as well as by energy plants that generate power to run theproduction process, cement production may be a leading source of currentcarbon dioxide atmospheric emissions. In addition to the pollutionproblems associated with Portland cement production, the structuresproduced with Portland cements may have a repair and maintenance expensebecause of the instability of the cured product produced from Portlandcement.

The compositions provided herein, may reduce the carbon foot print byusing the carbon dioxide emitted from the power plants or otherindustrial sources and sequestering them into the formation of thecompositions of the invention. Alternatively, the compositions providedherein may reduce the carbon foot print by using the subterraneancarbonated brines to prepare the compositions of the invention. Furtheralternatively, the compositions provided herein may reduce the carbonfoot print by producing the cement compositions that partially orcompletely replace the carbon emitting cements, such as OPC. Thecompositions of the invention may be mixed with OPC to give the cementmaterial with equal or higher strength, thereby reducing the amount ofOPC to make cement.

The compositions provided herein also show surprising and unexpectedproperties as the products obtained from the compositions (either aloneor in combination with OPC) have high compressive strength resulting inproducts with high durability and less maintenance costs. Thecompositions of the invention may also be optimized to result inmaterials with desired compressive strengths and thereby, furtherincreasing the efficiency of the process and reducing the cost ofproduction. For example, the compressive strength required for aroof-tile may not be as high as the compressive strength required forpillars. The compositions of the invention and the process to make thecement products from the compositions of the invention may be optimizedto result in cement products with desired compressive strength.

Additionally, the methods of the invention may be optimized to givecompositions that differ in their reactivity with water or with othercement. For example, the compositions of the invention may either beformed as hydraulic cement compositions or as a supplementarycementitious material or as a self-cementing material depending on theirreactivity with water. In some embodiments, the SCM compositions of theinvention may be mixed with Portland cement to result in the cement withan equal or higher compressive strength than the Portland cement itselfor the Portland cement in combination with other SCM known in the art.

Before the present invention is described in greater detail, it is to beunderstood that this invention is not limited to particular embodimentsdescribed, as such may, of course, vary. It is also to be understoodthat the terminology used herein is for the purpose of describingparticular embodiments only, and is not intended to be limiting, sincethe scope of the present invention will be limited only by the appendedclaims.

Where a range of values is provided, it is understood that eachintervening value, to the tenth of the unit of the lower limit unlessthe context clearly dictates otherwise, between the upper and lowerlimit of that range and any other stated or intervening value in thatstated range, is encompassed within the invention. The upper and lowerlimits of these smaller ranges may independently be included in thesmaller ranges and are also encompassed within the invention, subject toany specifically excluded limit in the stated range. Where the statedrange includes one or both of the limits, ranges excluding either orboth of those included limits are also included in the invention.

Certain ranges are presented herein with numerical values being precededby the term “about.” The term “about” is used herein to provide literalsupport for the exact number that it precedes, as well as a number thatis near to or approximately the number that the term precedes. Indetermining whether a number is near to or approximately a specificallyrecited number, the near or approximating unrequited number may be anumber, which, in the context in which it is presented, provides thesubstantial equivalent of the specifically recited number.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although any methods andmaterials similar or equivalent to those described herein can also beused in the practice or testing of the present invention, representativeillustrative methods and materials are now described.

All publications and patents cited in this specification are hereinincorporated by reference as if each individual publication or patentwere specifically and individually indicated to be incorporated byreference and are incorporated herein by reference to disclose anddescribe the methods and/or materials in connection with which thepublications are cited. The citation of any publication is for itsdisclosure prior to the filing date and should not be construed as anadmission that the present invention is not entitled to antedate suchpublication by virtue of prior invention. Further, the dates ofpublication provided may be different from the actual publication dateswhich may need to be independently confirmed.

It is noted that, as used herein and in the appended claims, thesingular forms “a,” “an,” and “the” include plural references unless thecontext clearly dictates otherwise. It is further noted that the claimsmay be drafted to exclude any optional element. As such, this statementis intended to serve as antecedent basis for use of such exclusiveterminology as “solely,” “only” and the like in connection with therecitation of claim elements, or use of a “negative” limitation.

As will be apparent to those of skill in the art upon reading thisdisclosure, each of the individual embodiments described and illustratedherein has discrete components and features which may be readilyseparated from or combined with the features of any of the other severalembodiments without departing from the scope or spirit of the presentinvention. Any recited method can be carried out in the order of eventsrecited or in any other order which is logically possible.

I. Compositions

Aspects of the invention include compositions including hydrauliccement, supplementary cemetitious material (SCM), and self-cementingcomposition, where the hydraulic cement or the SCM or the self-cementingcomposition includes metastable and stable carbonate forms such as,vaterite, amorphous calcium carbonate (ACC), aragonite, calcite, ikaite,a precursor phase of vaterite, a precursor phase of aragonite, anintermediary phase that is less stable than calcite, polymorphic formsin between these polymorphs, and combination thereof. The precursor ofvaterite, vaterite, precursor of aragonite, and aragonite can beutilized as a reactive metastable calcium carbonate forms for reactionpurposes and stabilization reactions, such as cementing.

The metastable forms such as vaterite and precursor to vaterite andstable carbonate forms, such as, calcite, may have varying degrees ofsolubility so that they may dissolve when hydrated in aqueous solutionsand reprecipitate stable carbonate minerals, such as calcite and/oraragonite.

The compositions of the invention including metastable forms, such asvaterite, surprisingly and unexpectedly are stable compositions in a drypowdered form or in a slurry containing saltwater. The metastable formsin the compositions of the invention may not completely convert to thestable forms, such as calcite, for cementation until contacted withfresh water.

Vaterite may be present in monodisperse or agglomerated form, and may bein spherical, ellipsoidal, plate like shape, or hexagonal system.Vaterite typically has a hexagonal crystal structure and formspolycrystalline spherical particles upon growth. The precursor form ofvaterite comprises nanoclusters of vaterite and the precursor form ofaragonite comprises sub-micron to nanoclusters of aragonite needles.Aragonite, if present in the composition, may be needle shaped,columnar, or crystals of the rhombic system. Calcite, if present, may becubic, spindle, or crystals of hexagonal system. An intermediary phasethat is less stable than calcite may be a phase that is between vateriteand calcite, a phase between precursor of vaterite and calcite, a phasebetween aragonite and calcite, and/or a phase between precursor ofaragonite and calcite.

In some embodiments, the compositions of the invention are syntheticcompositions and are not naturally occurring. In some embodiments, thecomposition of the invention is in a powder form. In some embodiments,the composition of the invention is in a dry powder form. In someembodiments, the composition of the invention is disordered or is not inan ordered array or is in the powdered form. In still some embodiments,the composition of the invention is in a partially or wholly hydratedform. In still some embodiments, the composition of the invention is insaltwater or fresh water. In still some embodiments, the composition ofthe invention is in water containing sodium chloride. In still someembodiments, the composition of the invention is in water containingalkaline earth metal ions, such as, but are not limited to, calcium,magnesium, etc.

The compositions provided herein show unexpected properties, such as,high compressive strength, high durability, and less maintenance costs.In addition, in some embodiments, when the CO₂ is sequestered from fluegas or from carbonated brines into the calcium carbonate forms of theinvention, it reduces carbon footprint and provides cleaner environment.In some embodiments, the compositions upon combination with water,setting, and hardening, have a compressive strength of at least 14 MPa(megapascal) or in some embodiments, between 14-80 MPa or 14-35 MPa. Insome embodiments, the vaterite containing compositions provided hereinare formed from CO₂ source that has a fossil fuel origin. Accordingly,in some embodiments, the compositions provided herein have a carbonisotopic fractionation value (δ¹³C) of less than −12‰. In someembodiments, the compositions of the invention are non-medical or arenot for medical procedures. In some embodiments, the compositions of theinvention are synthetic compositions and are not naturally occurring.

In a first aspect, there is provided a composition including hydrauliccement where the hydraulic cement includes at least 47% w/w vaterite,wherein the composition upon combination with water, setting, andhardening has a compressive strength of at least 14 MPa. In a secondaspect, there is provided a composition including a hydraulic cementwhere the hydraulic cement includes at least 47% w/w vaterite, whereinthe composition has a δ¹³C of less than −12‰. As used herein, “hydrauliccement” includes a composition which sets and hardens after combiningwith water or a solution where the solvent is water, e.g., an admixturesolution. After hardening, the compositions retain strength andstability even under water. As a result of the immediately startingreactions, stiffening can be observed which may increase with time.After reaching a certain level, this point in time may be referred to asthe start of setting. The consecutive further consolidation may becalled setting, after which the phase of hardening begins. Thecompressive strength of the material may then grow steadily, over aperiod which ranges from a few days in the case of“ultra-rapid-hardening” cements, to several months or years in the caseof other cements. Setting and hardening of the product produced bycombination of the composition of the invention with an aqueous liquidmay or may not result from the production of hydrates that may be formedfrom the composition upon reaction with water, where the hydrates areessentially insoluble in water. Cements may be employed by themselves orin combination with aggregates, both coarse and fine, in which case thecompositions may be referred to as concretes or mortars. Cements mayalso be cut and chopped to form aggregates.

In a third aspect, there is provided a composition including asupplementary cementitious material (SCM) where the SCM includes atleast 47% w/w vaterite, wherein the composition upon combination withwater or water and cement; setting; and hardening, has a compressivestrength of at least 14 MPa. In a fourth aspect, there is provided acomposition including a SCM where the SCM includes at least 47% w/wvaterite, wherein the composition has a carbon isotopic fractionationvalue (δ¹³C) of less than −12‰.

As used herein, “supplementary cementitious material” (SCM) includes SCMas is well known in the art. For example, when SCM of the invention ismixed with Portland cement, one or more properties of that Portlandcement after interaction with SCM substantially remain unchanged or areenhanced as compared to the Portland cement itself without SCM or thePortland cement mixed with conventional SCM (such as fly ash). Theproperties include, but are not limited to, fineness, soundness,consistency, setting time of cement, hardening time of cement,rheological behavior, hydration reaction, specific gravity, loss ofignition, and/or hardness, such as compressive strength of the cement.For example, when 20% of SCM of the invention is added to 80% of OPC(ordinary Portland cement), the one or more properties, such as, e.g.,compressive strength, of OPC either remain unchanged, decrease by nomore than 10%, or are enhanced. The properties of Portland cement mayvary depending on the type of Portland cement. The substitution ofPortland cement with the SCM of the invention may reduce the CO₂emissions without compromising the performance of the cement or theconcrete as compared to regular Portland cement.

In some embodiments, maximum replacement volume of Portland cement withthe SCM of the invention can be determined by carrying out variousperformace tests on cement and/or concrete, after mixing the SCM withOPC (for cement) and aggregate and/or sand (for concrete). Such testscan be used as parameters for testing the amount of the SCM of theinvention that can be used to replace the OPC. The property, such as,fineness of the cement, for example, may affect the rate of hydration.Greater fineness may increase the surface available for hydration,causing greater early strength and more rapid generation of heat. TheWagner Turbidimeter and the Blaine air permeability test for measuringcement fineness are both required by the American Society for TestingMaterials (ASTM) and the American Association for State HighwayTransportation Officials (AASHTO). Soundness, which is the ability ofhardened cement paste to retain its volume after setting, can becharacterized by measuring the expansion of mortar bars in an autoclave.The compressive strength of 2-inch (50-mm) mortar cubes after 7 days maynot be less than 2,800 psi (19.3 MPa) for Type I cement.

In some embodiments, Portland clinker may be inter-ground with the SCMof the invention to give Portland cement blend. The amount of SCM addedto the Portland clinker may be optimized based on the size and thedistribution of the particles in the blend. In some embodiments, on anaverage, the finely ground SCM of the invention is half the size of theparticle of the clinker which in turn is smaller than the clinkerparticle size in regular Portland cement. This may provide the blendwith a particle packing effect, which may increase the strength of theconcrete.

In some embodiments, the vaterite in the SCM composition of theinvention may react with the Portland cement or Portland clinker. Insome embodiments, the aluminates from the clinker fraction may combinewith the carbonate of the SCM to form carboaluminates which may reducethe porosity of the concrete and increase its strength. In someembodiments, the SCM composition of the invention may act as a filler.In some embodiments, the size of the particles and/or the surface areaof the particles may affect the interaction of the SCM composition ofthe invention with the Portland cement or Portland clinker. In someembodiments, the SCM composition of the invention may provide nucleationsites for the Portland cement or the Portland clinker. In someembodiments, the SCM composition of the invention may possess acombination of the foregoing embodiments.

Examples of such tests for concrete include, but are not limited to,concrete compressive strength, concrete flexural strength, conceretsplitting tensile strength, concrete modulus of elasticity, concreteshrinkage, concrete resistance to alkali-silica reactivity, concreteresistance to sulfate attack, concrete resistance to freezing andthawing, concrete resistance to scaling, and concrete resistance topassage of chloride ions.

In some embodiments, the SCM composition of the invention may differfrom the hydraulic cement composition of the invention in reactivity. Insome embodiments, the SCM composition of the invention may not be aneffective hydraulic cement composition and vice versa. For example, insome embodiments, the SCM composition of the invention alone uponcombination with water, setting and hardening may not result in the samecompressive strength as the hydraulic cement composition of theinvention upon combination with water, setting and hardening. However,such SCM composition upon mixing with other cement, such as, Portlandcement gives surprisingly and unexpectedly high compressive strengths,as described below.

In some embodiments, there is provided a composition including asupplementary cementitious material (SCM) where the SCM includes atleast 50% w/w calcite, wherein the composition upon combination withwater or water and cement; setting; and hardening, has a compressivestrength of at least 14 MPa. In a fourth aspect, there is provided acomposition including a SCM where the SCM includes at least 50% w/wcalcite, wherein the composition has a carbon isotopic fractionationvalue (δ¹³C) of less than −12‰. In some embodiments, the calcite in theforegoing embodiments is between 50-100% w/w; or between 50-99% w/w; orbetween 50-95% w/w; or between 50-90% w/w; or between 50-85% w/w; orbetween 50-80% w/w; or between 50-70% w/w; or between 50-60% w/w; orbetween 50-55% w/w. In some embodiments, the foregoing SCM compositioncontaining at least 50% w/w calcite, further comprises vaterite,aragonite, or ACC in at least 1% w/w, or 10% w/w, or 50% w/w, or between1-50% w/w.

In a fifth aspect, there is provided a composition including a SCM,wherein at least 16% by wt of SCM mixed with OPC results in no more than10% reduction in compressive strength of OPC at 28 days as compared toOPC alone. In a sixth aspect, there is provided a composition includinga SCM, wherein at least 16% by wt of SCM mixed with OPC results in morethan 5% increase in compressive strength of OPC at 28 days as comparedto OPC alone.

In some embodiments, at least 17% by wt of SCM; or at least 18% by wt ofSCM; or at least 19% by wt of SCM; or at least 20% by wt of SCM; or atleast 21% by wt of SCM; or at least 22% by wt of SCM; or at least 23% bywt of SCM; or at least 24% by wt of SCM; or at least 25% by wt of SCM;or at least 30% by wt of SCM; or at least 40% by wt of SCM; or at least50% by wt of SCM; or between 16-50% by wt of SCM; or between 16-40% bywt of SCM; or between 16-30% by wt of SCM; or between 16-25% by wt ofSCM; or between 16-22% by wt of SCM; or between 16-20% by wt of SCM; orbetween 16-18% by wt of SCM; or between 18-50% by wt of SCM; or between18-40% by wt of SCM; or between 18-30% by wt of SCM; or between 18-20%by wt of SCM; or between 20-50% by wt of SCM; or between 20-40% by wt ofSCM; or between 20-30% by wt of SCM; or between 30-50% by wt of SCM; orbetween 30-40% by wt of SCM; or between 40-50% by wt of SCM; or 16% bywt of SCM; or 17% by wt of SCM; or 18% by wt of SCM; or 19% by wt ofSCM; or 20% by wt of SCM; or 22% by wt of SCM; or 25% by wt of SCM;mixed with OPC results in no more than 10% reduction in compressivestrength of OPC at 28 days, as compared to OPC alone or results in morethan 5% increase in compressive strength of OPC at 28 days as comparedto OPC alone. For example, at least 17-20% by wt of SCM or 20% by wt ofSCM mixed with OPC results in no more than 10% reduction in thecompressive strength of OPC at 28 days, as compared to OPC alone orresults in more than 5% increase in compressive strength of OPC at 28days as compared to OPC alone.

In some embodiments, the compressive strength of Portland cement is in arange of 17-45 MPa. Accordingly, in some embodiments, there is provideda composition including a SCM, wherein at least 16% by wt of SCM mixedwith OPC results in no more than 10% reduction in compressive strengthof OPC at 28 days wherein the compressive strength of OPC is in a rangeof 17-45 MPa. In some embodiments, there is provided a compositionincluding a SCM, wherein at least 16% by wt of SCM mixed with OPCresults in more than 5% increase in compressive strength of OPC at 28days wherein the compressive strength of OPC is in a range of 17-45 MPa.In some embodiments, the compressive strength of Portland cement is in arange of 17-40 MPa; or in a range of 17-35 MPa; or in a range of 17-30MPa; or in a range of 17-25 MPa; or in a range of 17-23 MPa; or in arange of 17-22 MPa; or in a range of 17-21 MPa; or in a range of 17-20MPa; or in a range of 17-19 MPa; or in a range of 17-18 MPa; or in arange of 18-35 MPa; or in a range of 20-35 MPa; or in a range of 18-25MPa. For example, in some embodiments, the compressive strength ofPortland cement is in a range of 17-35 MPa.

The compressive strength of OPC may vary depending on the type of OPC.The types of OPC include, Type I, Type II, Type III, Type IV, Type V,Type IA, Type IIA, and Type IIIA. Table I illustrates the compressivestrength (in MPa) of various types of Portland cement at 1 day, 3 days,7 days, and 28 days of curing time.

TABLE I Portland cement type Curing time I IA II IIA III IIIA IV V 1day  — — — — 12.4 10.0 — — 3 days 12.4 10.0 10.3  8.3 24.1 19.3 —  8.3 7days 19.3 15.5 17.2 13.8 — —  6.9 15.2 28 days  — — — — — — 17.2 20.7

In some embodiments, at least 16% by wt of SCM mixed with OPC results inno more than 10%; or no more than 9%; or no more than 8%; or no morethan 7%; or no more than 6%; or no more than 5%; or no more than 4%; orno more than 3%; or no more than 2%; or no more than 1%; or no more than1-5%; or no more than 5-10%; or no more than 6-10%; or no more than8-10%; reduction in compressive strength of OPC at 28 days as comparedto OPC alone or as compared to the compressive strength of Portlandcement in a range of 17-45 MPa. In some embodiments, at least 16% by wtof SCM mixed with OPC results in no more than 5 MPa; or no more than 4MPa; or no more than 3 MPa; or no more than 2 MPa; or no more than 1MPa; or no more than 0.5 MPa; or no more than 0.5-1 MPa; or no more than0.5-2 MPa; or no more than 0.5-3 MPa, or no more than 0.5-5 MPa,reduction in compressive strength of OPC at 28 days as compared to OPCalone or as compared to the compressive strength of Portland cement in arange of 17-45 MPa.

In some embodiments, there is provided a composition including a SCM,wherein at least 16% by wt of SCM mixed with OPC results in more than5%; or more than 8%; or more than 10%; or more than 15%; or more than20%; or more than 25%; or more than 30%; or more than 5-10%; or morethan 5-15%; or more than 5-8%; or more than 5-20%; or more than 5-30%,increase in compressive strength of OPC at 28 days as compared to OPCalone or as compared to the compressive strength of Portland cement in arange of 17-45 MPa. In some embodiments, there is provided a compositionincluding a SCM, wherein the at least 16% by wt of SCM mixed with OPCresults in between 1-20 MPa; or between 1-15 MPa; or between 1-12 MPa;or between 1-10 MPa; or between 1-8 MPa; or between 1-5 MPa; or between1-4 MPa; or between 1-3 MPa; or between 1-2 MPa; or 1 or 2 or 3 MPa; ormore than 1 MPa, increase in compressive strength of OPC at 28 days whencompared to OPC alone or as compared to the compressive strength ofPortland cement in a range of 17-45 MPa.

In a seventh aspect, there is provided a self-cementing compositionincluding at least 1% w/w vaterite in saltwater, wherein the compositionupon rinsing with fresh water, setting, and hardening has a compressivestrength of at least 14 MPa. The self-cementing composition of theinvention is in saltwater. As used herein, the “saltwater” is employedin its conventional sense to include a number of different types ofaqueous medium other than fresh water, including, but not limited tobrackish water, sea water, brine (including man-made brines, e.g.,geothermal plant wastewaters, desalination waste waters, etc), as wellas other salines having a salinity that is greater than that offreshwater. Brine is water saturated or nearly saturated with salt andhas a salinity that is 50 ppt (parts per thousand) or greater. Brackishwater is water that is saltier than fresh water, but not as salty asseawater, having a salinity ranging from 0.5 to 35 ppt. Seawater iswater from a sea or ocean and has a salinity ranging from 35 to 50 ppt.The saltwater source from which the composition of the invention isderived may be a naturally occurring source, such as a sea, ocean, lake,swamp, estuary, lagoon, etc., or a man-made source. In some embodiments,the saltwater includes water containing more than 1% chloride content,such as, NaCl; or more than 10% NaCl; or more than 20% NaCl; or morethan 30% NaCl; or more than 40% NaCl; or more than 50% NaCl; or morethan 60% NaCl; or more than 70% NaCl; or more than 80% NaCl; or morethan 90% NaCl; or between 1-95% NaCl; or between 10-95% NaCl; or between20-95% NaCl; or between 30-95% NaCl; or between 40-95% NaCl; or between50-95% NaCl; or between 60-95% NaCl; or between 70-95% NaCl; or between80-95% NaCl; or between 90-95% NaCl.

In some embodiments, the self-cementing composition that is in saltwaterincludes less than 90% by wt solid material; or less than 80% by wtsolid material; or less than 70% by wt solid material; or less than 60%by wt solid material; or less than 50% by wt solid material; or lessthan 40% by wt solid material; or less than 30% by wt solid material; orless than 20% by wt solid material; or less than 10% by wt solidmaterial; or between 10-90% by wt solid material; or between 10-80% bywt solid material; or between 10-70% by wt solid material; or between10-50% by wt solid material; or between 10-30% by wt solid material; orbetween 40-90% by wt solid material; or between 50-90% by wt solidmaterial.

The self-cementing composition need not be dewatered and dried to makethe hydraulic cement. Such composition can be simply dewatered, washedwith water to partially or completely remove chloride, such as, sodiumchloride, optionally dewatered again, and poured into molds where itsets and hardens to form a rock, pre-cast or pre-formed buildingmaterials. The rock can be further processed to make aggregates. Suchabsence of the step of drying saves energy, reduces the carbon footprint, and provides a cleaner environment. This composition may or maynot include a binder. In some embodiments, the self-cementingcomposition does not include a binder. In some embodiments, theinvention provides a self-cementing composition that does not containbinders and leads to a self-cementing synthetic rock. The methods of theinvention allow for production of a hard, durable rock through processesthat involve physical reactions without the need for extrinsic orintrinsic binders. Thus, in some embodiments the invention providesself-cementing composition that contains less than 10, 5, 2, 1, 0.5,0.2, 0.1, 0.05, 0.02, 0.01, 0.005, 0.001, 0.0005, 0.0001% w/w of binder,where binder includes compounds or substances that are added to aself-cementing composition in order to cause or promote chemicalreactions that cause components of the self-cementing composition tobind together during a synthetic process. Examples of binders include,but are not limited to, acrylic polymer liquid, lime, volcanic ash, etc.In some embodiments, the self-cementing composition of the inventionincludes substantially no binder.

Such self-cementing composition can be artificially lithified inprocesses that mimic geologic processes in which physical, rather thanchemical, processes are the processes by which rocks are formed, e.g.,dissolution and reprecipitation of compounds in new forms that serve tobind the composition together. Such self-cementing composition, incertain embodiments, contains one or more carbonate compounds, e.g.,carbonate compounds derived from a fossil fuel source. Theself-cementing composition may in some embodiments have a carbonisotopic fractionation (δ¹³C) value more negative than (less than) −12‰,or −13‰, or −14‰, or −15‰ or −18‰, or −22‰, or −26‰ or −30‰, or −32‰, or−36‰, as described herein in detail.

The self-cementing composition when rinsed with water may lead to asynthetic rock in a process in which polymorphs recited herein, such as,vaterite, is converted to more stable components, such as aragonite,calcite, or combination thereof. For example, in some embodiments, thesynthetic rock is produced from the self-cementing composition in aprocess where aragonite is converted to calcite, and/or vaterite isconverted to aragaonite and/or calcite.

In some embodiments of the foregoing aspects, the composition includesat least 47% w/w vaterite; or at least 50% w/w vaterite; or at least 60%w/w vaterite; or at least 70% w/w vaterite; or at least 75% w/wvaterite; or at least 80% w/w vaterite; or at least 85% w/w vaterite; orat least 90% w/w vaterite; or at least 95% w/w vaterite; or from 47% w/wto 100% w/w vaterite; or from 47% w/w to 99% w/w vaterite; or from 47%w/w to 95% w/w vaterite; or from 47% w/w to 90% w/w vaterite; or from47% w/w to 85% w/w vaterite; or from 47% w/w to 80% w/w vaterite; orfrom 47% w/w to 75% w/w vaterite; or from 47% w/w to 70% w/w vaterite;or from 47% w/w to 65% w/w vaterite; or from 47% w/w to 60% w/wvaterite; or from 47% w/w to 55% w/w vaterite; or from 47% w/w to 50%w/w vaterite; or from 50% w/w to 100% w/w vaterite; or from 50% w/w to90% w/w vaterite; or from 50% w/w to 80% w/w vaterite; or from 50% w/wto 75% w/w vaterite; or from 50% w/w to 70% w/w vaterite; or from 50%w/w to 60% w/w vaterite; or from 60% w/w to 100% w/w vaterite; or from60% w/w to 90% w/w vaterite; or from 60% w/w to 80% w/w vaterite; orfrom 60% w/w to 70% w/w vaterite; or from 70% w/w to 100% w/w vaterite;or from 70% w/w to 95% w/w vaterite; or from 70% w/w to 90% w/wvaterite; or from 70% w/w to 85% w/w vaterite; or from 70% w/w to 80%w/w vaterite; or from 70% w/w to 75% w/w vaterite; or from 80% w/w to100% w/w vaterite; or from 80% w/w to 95% w/w vaterite; or from 80% w/wto 90% w/w vaterite; or from 80% w/w to 85% w/w vaterite; or from 90%w/w to 100% w/w vaterite; or from 90% w/w to 99% w/w vaterite; or from90% w/w to 98% w/w vaterite; or from 90% w/w to 95% w/w vaterite; orfrom 90% w/w to 92% w/w vaterite; or 47% w/w vaterite; or 50% w/wvaterite; or 55% w/w vaterite; or 60% w/w vaterite; or 65% w/w vaterite;or 70% w/w vaterite; or 75% w/w vaterite; or 80% w/w vaterite; or 85%w/w vaterite; or 90% w/w vaterite; or 92% w/w vaterite; or 95% w/wvaterite; or 98% w/w vaterite; or 99% w/w vaterite.

In some embodiments of the foregoing aspects and the foregoingembodiment, the composition further includes ACC. In such compositions,the amount of ACC is at least 1% w/w; or at least 2% w/w ACC; or atleast 5% w/w ACC; or at least 10% w/w ACC; or at least 20% w/w ACC; orat least 30% w/w ACC; or at least 40% w/w ACC; or at least 50% w/w ACC;or at least 53% w/w ACC; or from 1% w/w to 53% w/w ACC; or from 1% w/wto 50% w/w ACC; or from 1% w/w to 40% w/w ACC; or from 1% w/w to 30% w/wACC; or from 1% w/w to 20% w/w ACC; or from 1% w/w to 10% w/w ACC; orfrom 5% w/w to 53% w/w ACC; or from 5% w/w to 50% w/w ACC; or from 5%w/w to 40% w/w ACC; or from 5% w/w to 30% w/w ACC; or from 5% w/w to 20%w/w ACC; or from 5% w/w to 10% w/w ACC; or from 10% w/w to 53% w/w ACC;or from 10% w/w to 50% w/w ACC; or from 10% w/w to 40% w/w ACC; or from10% w/w to 30% w/w ACC; or from 10% w/w to 20% w/w ACC; or from 20% w/wto 53% w/w ACC; or from 20% w/w to 50% w/w ACC; or from 20% w/w to 40%w/w ACC; or from 20% w/w to 30% w/w ACC; or from 30% w/w to 53% w/w ACC;or from 30% w/w to 50% w/w ACC; or from 30% w/w to 40% w/w ACC; or from40% w/w to 53% w/w ACC; or from 40% w/w to 50% w/w ACC; or from 50% w/wto 53% w/w ACC.

In an eighth aspect, there is provided a composition including ahydraulic cement where the hydraulic cement includes at least 10% w/wvaterite and at least 1% w/w amorphous calcium carbonate (ACC), whereinthe composition upon combination with water, setting, and hardening hasa compressive strength of at least 14 MPa. In a ninth aspect, there isprovided a composition including a hydraulic cement where the hydrauliccement includes at least 10% w/w vaterite and at least 1% w/w ACC,wherein the composition has a δ¹³C of less than −12‰.

In a tenth aspect, there is provided a composition including a SCM wherethe SCM includes at least 10% w/w vaterite and at least 1% w/w ACC,wherein the composition upon combination with water or water and cement;setting; and hardening has a compressive strength of at least 14 MPa. Inan eleventh aspect, there is provided a composition including a SCMwhere the SCM includes at least 10% w/w vaterite and at least 1% w/wamorphous calcium carbonate (ACC), wherein the composition has a δ¹³C ofless than −12%0.

In some embodiments of the foregoing aspects and embodiments, thecomposition includes at least 10% w/w vaterite; or at least 20% w/wvaterite; or at least 30% w/w vaterite; or at least 40% w/w vaterite; orat least 50% w/w vaterite; or at least 60% w/w vaterite; or at least 70%w/w vaterite; or at least 80% w/w vaterite; or at least 90% w/wvaterite; or at least 95% w/w vaterite; or at least 99% w/w vaterite; orfrom 10% w/w to 99% w/w vaterite; or from 10% w/w to 95% w/w vaterite;or from 10% w/w to 90% w/w vaterite; or from 10% w/w to 80% w/wvaterite; or from 10% w/w to 70% w/w vaterite; or from 10% w/w to 60%w/w vaterite; or from 10% w/w to 50% w/w vaterite; or from 10% w/w to40% w/w vaterite; or from 10% w/w to 30% w/w vaterite; or from 10% w/wto 20% w/w vaterite; or from 20% w/w to 99% w/w vaterite; or from 20%w/w to 95% w/w vaterite; or from 20% w/w to 90% w/w vaterite; or from20% w/w to 80% w/w vaterite; or from 20% w/w to 70% w/w vaterite; orfrom 20% w/w to 60% w/w vaterite; or from 20% w/w to 50% w/w vaterite;or from 20% w/w to 40% w/w vaterite; or from 20% w/w to 30% w/wvaterite; or from 20% w/w to 25% w/w vaterite; or from 30% w/w to 99%w/w vaterite; or from 30% w/w to 95% w/w vaterite; or from 30% w/w to90% w/w vaterite; or from 30% w/w to 80% w/w vaterite; or from 30% w/wto 70% w/w vaterite; or from 30% w/w to 60% w/w vaterite; or from 30%w/w to 50% w/w vaterite; or from 30% w/w to 40% w/w vaterite; or from40% w/w to 99% w/w vaterite; or from 40% w/w to 95% w/w vaterite; orfrom 40% w/w to 90% w/w vaterite; or from 40% w/w to 80% w/w vaterite;or from 40% w/w to 70% w/w vaterite; or from 40% w/w to 60% w/wvaterite; or from 40% w/w to 50% w/w vaterite; or from 50% w/w to 99%w/w vaterite; or from 50% w/w to 95% w/w vaterite; or from 50% w/w to90% w/w vaterite; or from 50% w/w to 80% w/w vaterite; or from 50% w/wto 70% w/w vaterite; or from 50% w/w to 60% w/w vaterite; or from 60%w/w to 99% w/w vaterite; or from 60% w/w to 95% w/w vaterite; or from60% w/w to 90% w/w vaterite; or from 60% w/w to 80% w/w vaterite; orfrom 60% w/w to 70% w/w vaterite; or from 70% w/w to 99% w/w vaterite;or from 70% w/w to 95% w/w vaterite; or from 70% w/w to 90% w/wvaterite; or from 70% w/w to 80% w/w vaterite; or from 80% w/w to 99%w/w vaterite; or from 80% w/w to 95% w/w vaterite; or from 80% w/w to90% w/w vaterite; or from 90% w/w to 99% w/w vaterite; or from 90% w/wto 95% w/w vaterite; or 10% w/w vaterite; or 20% w/w vaterite; or 30%w/w vaterite; or 40% w/w vaterite; or 50% w/w vaterite; or 60% w/wvaterite; or 70% w/w vaterite; or 75% w/w vaterite; or 80% w/w vaterite;or 85% w/w vaterite; or 90% w/w vaterite; or 95% w/w vaterite; or 99%w/w vaterite.

In some embodiments of the foregoing aspects and the foregoingembodiments, the hydraulic cement includes at least 1% w/w amorphouscalcium carbonate (ACC); or at least 2% w/w ACC; or at least 5% w/w ACC;or at least 10% w/w ACC; or at least 20% w/w ACC; or at least 30% w/wACC; or at least 40% w/w ACC; or at least 50% w/w ACC; or at least 60%w/w ACC; or at least 70% w/w ACC; or at least 80% w/w ACC; or at least90% w/w ACC; or from 1% w/w to 90% w/w ACC; or from 1% w/w to 80% w/wACC; or from 1% w/w to 70% w/w ACC; or from 1% w/w to 60% w/w ACC; orfrom 1% w/w to 50% w/w ACC; or from 1% w/w to 40% w/w ACC; or from 1%w/w to 30% w/w ACC; or from 1% w/w to 20% w/w ACC; or from 1% w/w to 10%w/w ACC; or from 5% w/w to 90% w/w ACC; or from 5% w/w to 80% w/w ACC;or from 5% w/w to 70% w/w ACC; or from 5% w/w to 60% w/w ACC; or from 5%w/w to 50% w/w ACC; or from 5% w/w to 40% w/w ACC; or from 5% w/w to 30%w/w ACC; or from 5% w/w to 20% w/w ACC; or from 5% w/w to 10% w/w ACC;or from 10% w/w to 90% w/w ACC; or from 10% w/w to 80% w/w ACC; or from10% w/w to 70% w/w ACC; or from 10% w/w to 60% w/w ACC; or from 10% w/wto 50% w/w ACC; or from 10% w/w to 40% w/w ACC; or from 10% w/w to 30%w/w ACC; or from 10% w/w to 20% w/w ACC; or from 20% w/w to 90% w/w ACC;or from 20% w/w to 80% w/w ACC; or from 20% w/w to 70% w/w ACC; or from20% w/w to 60% w/w ACC; or from 20% w/w to 50% w/w ACC; or from 20% w/wto 40% w/w ACC; or from 20% w/w to 30% w/w ACC; or from 30% w/w to 90%w/w ACC; or from 30% w/w to 80% w/w ACC; or from 30% w/w to 70% w/w ACC;or from 30% w/w to 60% w/w ACC; or from 30% w/w to 50% w/w ACC; or from30% w/w to 40% w/w ACC; or from 40% w/w to 90% w/w ACC; or from 40% w/wto 80% w/w ACC; or from 40% w/w to 70% w/w ACC; or from 40% w/w to 60%w/w ACC; or from 40% w/w to 50% w/w ACC; or from 50% w/w to 90% w/w ACC;or from 50% w/w to 80% w/w ACC; or from 50% w/w to 70% w/w ACC; or from50% w/w to 60% w/w ACC; or from 60% w/w to 90% w/w ACC; or from 60% w/wto 80% w/w ACC; or from 60% w/w to 70% w/w ACC; or from 60% w/w to 65%w/w ACC; or from 70% w/w to 90% w/w ACC; or from 70% w/w to 80% w/w ACC;or from 70% w/w to 75% w/w ACC; or from 80% w/w to 90% w/w ACC; or from80% w/w to 85% w/w ACC; or from 85% w/w to 90% w/w ACC; or 1% w/w ACC;or 2% w/w ACC; or 5% w/w ACC; or 10% w/w ACC; or 20% w/w ACC; or 30% w/wACC; or 40% w/w ACC; or 50% w/w ACC; or 60% w/w ACC; or 70% w/w ACC; or80% w/w ACC; or 90% w/w ACC.

In some embodiments of the foregoing aspects and the foregoingembodiments, the composition includes the vaterite in a range of 10% w/wto 99% w/w and the ACC in a range of 1% w/w to 90% w/w; or the vateriteis in a range of 10% w/w to 90% w/w and the ACC is in a range of 10% w/wto 90% w/w; or the vaterite is in a range of 10% w/w to 80% w/w and theACC is in a range of 20% w/w to 90% w/w; or the vaterite is in a rangeof 10% w/w to 70% w/w and the ACC is in a range of 30% w/w to 90% w/w;or the vaterite is in a range of 10% w/w to 60% w/w and the ACC is in arange of 40% w/w to 90% w/w; or the vaterite is in a range of 10% w/w to50% w/w and the ACC is in a range of 50% w/w to 90% w/w; or the vateriteis in a range of 10% w/w to 40% w/w and the ACC is in a range of 60% w/wto 90% w/w; or the vaterite is in a range of 10% w/w to 30% w/w and theACC is in a range of 70% w/w to 90% w/w; or the vaterite is in a rangeof 10% w/w to 20% w/w and the ACC is in a range of 80% w/w to 90% w/w.It is to be understood that the percentage of each of the components inthe composition will be in such a way that the total percentage of thecomponents in the composition may not exceed a total of 100% by wt.

In some embodiments of the foregoing aspects and the foregoingembodiments, the composition after setting, and hardening has acompressive strength of at least 14 MPa; or at least 16 MPa; or at least18 MPa; or at least 20 MPa; or at least 25 MPa; or at least 30 MPa; orat least 35 MPa; or at least 40 MPa; or at least 45 MPa; or at least 50MPa; or at least 55 MPa; or at least 60 MPa; or at least 65 MPa; or atleast 70 MPa; or at least 75 MPa; or at least 80 MPa; or at least 85MPa; or at least 90 MPa; or at least 95 MPa; or at least 100 MPa; orfrom 14-100 MPa; or from 14-80 MPa; or from 14-75 MPa; or from 14-70MPa; or from 14-65 MPa; or from 14-60 MPa; or from 14-55 MPa; or from14-50 MPa; or from 14-45 MPa; or from 14-40 MPa; or from 14-35 MPa; orfrom 14-30 MPa; or from 14-25 MPa; or from 14-20 MPa; or from 14-18 MPa;or from 14-16 MPa; or from 17-35 MPa; or from 17-30 MPa; or from 17-25MPa; or from 17-20 MPa; or from 17-18 MPa; or from 20-100 MPa; or from20-90 MPa; or from 20-80 MPa; or from 20-75 MPa; or from 20-70 MPa; orfrom 20-65 MPa; or from 20-60 MPa; or from 20-55 MPa; or from 20-50 MPa;or from 20-45 MPa; or from 20-40 MPa; or from 20-35 MPa; or from 20-30MPa; or from 20-25 MPa; or from 30-100 MPa; or from 30-90 MPa; or from30-80 MPa; or from 30-75 MPa; or from 30-70 MPa; or from 30-65 MPa; orfrom 30-60 MPa; or from 30-55 MPa; or from 30-50 MPa; or from 30-45 MPa;or from 30-40 MPa; or from 30-35 MPa; or from 40-100 MPa; or from 40-90MPa; or from 40-80 MPa; or from 40-75 MPa; or from 40-70 MPa; or from40-65 MPa; or from 40-60 MPa; or from 40-55 MPa; or from 40-50 MPa; orfrom 40-45 MPa; or from 50-100 MPa; or from 50-90 MPa; or from 50-80MPa; or from 50-75 MPa; or from 50-70 MPa; or from 50-65 MPa; or from50-60 MPa; or from 50-55 MPa; or from 60-100 MPa; or from 60-90 MPa; orfrom 60-80 MPa; or from 60-75 MPa; or from 60-70 MPa; or from 60-65 MPa;or from 70-100 MPa; or from 70-90 MPa; or from 70-80 MPa; or from 70-75MPa; or from 80-100 MPa; or from 80-90 MPa; or from 80-85 MPa; or from90-100 MPa; or from 90-95 MPa; or 14 MPa; or 16 MPa; or 18 MPa; or 20MPa; or 25 MPa; or 30 MPa; or 35 MPa; or 40 MPa; or 45 MPa. For example,in some embodiments of the foregoing aspects and the foregoingembodiments, the composition after setting, and hardening has acompressive strength of 14 MPa to 40 MPa; or 17 MPa to 40 MPa; or 20 MPato 40 MPa; or 30 MPa to 40 MPa; or 35 MPa to 40 MPa. In someembodiments, the compressive strengths described herein are thecompressive strengths after 1 day, or 3 days, or 7 days, or 28 days, or56 days, or longer.

The calcium carbonate in the compositions of the invention may containcarbon dioxide from any number of sources including, but not limited to,an industrial waste stream including flue gas from combustion; a fluegas from a chemical processing plant; a flue gas from a plant thatproduces CO₂ as a byproduct; or combination thereof. In someembodiments, the carbon dioxide sequestered into the calcium carbonatein the compositions of the invention, originates from the burning offossil fuel, and thus some (e.g., at least 10, 50, 60, 70, 80, 90, 95%)or substantially all (e.g., at least 99, 99.5, or 99.9%) of the carbonin the carbonates is of fossil fuel origin, i.e., of plant origin.Typically, carbon of plant origin has a different ratio of stableisotopes (¹³C and ¹²C) than carbon of inorganic origin. The plants fromwhich fossil fuels are derived preferentially utilize ¹²C over ¹³C, thusfractionating the carbon isotopes so that the value of their ratiodiffers from that in the atmosphere in general. This value, whencompared to a standard value (PeeDee Belemnite, or PDB, standard), istermed the carbon isotopic fractionation (δ¹³C) value. Typically, δ¹³Cvalues for coal are in the range −30 to −20‰; δ¹³C values for methanemay be as low as −20‰ to −40‰ or even −40‰ to −80‰; δ¹³C values foratmospheric CO₂ are −10‰ to −7‰; for limestone +3‰ to −3‰; and formarine bicarbonate, 0‰.

In some embodiments, the carbon in the vaterite and/or other polymorphsin the composition of the invention, has a δ¹³C of less than −12‰, −13‰,−14‰, −15‰, −20‰, or less than −25‰, or less than −30‰, or less than−35‰, or less than −45‰, or less than −50‰, as described in furtherdetail herein. In some embodiments, the composition of the inventionincludes a CO₂-sequestering additive including carbonates, such as,vaterite, bicarbonates, or a combination thereof, in which thecarbonates, bicarbonates, or a combination thereof have a carbonisotopic fractionation (δ¹³C) value less than −12‰.

The relative carbon isotope composition (δ¹³C) value with units of ‰(per mille) is a measure of the ratio of the concentration of two stableisotopes of carbon, namely ¹²C and ¹³C, relative to a standard offossilized belemnite (the PDB standard).δ¹³ C‰=[(¹³ C/ ¹² C _(sample)−¹³ C/ ¹² C _(PDB standard))/(¹³ C/ ¹² C_(PDB standard))]×1000

¹²C is preferentially taken up by plants during photosynthesis and inother biological processes that use inorganic carbon because of itslower mass. The lower mass of ¹²C allows for kinetically limitedreactions to proceed more efficiently than with ¹³C. Thus, materialsthat are derived from plant material, e.g., fossil fuels, have relativecarbon isotope composition values that are less than those derived frominorganic sources. The carbon dioxide in flue gas produced from burningfossil fuels reflects the relative carbon isotope composition values ofthe organic material that was fossilized.

Material incorporating carbon from fossil fuels reflects δ¹³C valuesthat are like those of plant derived material, i.e. less than that whichincorporates carbon from atmospheric or non-plant marine sources. Theδ¹³C value of the material produced by the carbon dioxide from theburning fossil fuels can be verified by measuring the δ¹³C value of thematerial and confirming that it is not similar to the values foratmospheric carbon dioxide or marine sources of carbon. Table II belowlists relative carbon isotope composition (δ¹³C) value ranges forvarious carbon sources for comparison.

TABLE II δ¹³C Range δ¹³C Average value Carbon Source [‰] [‰] C3 Plants(most higher −23 to −33 −27 plants) C4 Plants (most tropical and  −9 to−16 −13 marsh plants) Atmosphere −6 to −7 −6 Marine Carbonate (CO₃) −2to +2 0 Marine Bicarbonate (HCO₃) −3 to +1 −1 Coal from Yallourn Seam in−27.1 to −23.2 −25.5 Australia¹ Coal from Dean Coal Bed in −24.47 to−25.14 −24.805 Kentucky, USA² ¹Holdgate, G. R. et al., Global andPlanetary Change, 65 (2009) pp. 89-103. ²Elswick, E. R. et al., AppliedGeochemistry, 22 (2007) pp. 2065-2077.

In some embodiments, the invention provides a method of characterizingthe composition of the invention by measuring its δ¹³C value. Anysuitable method may be used for measuring the δ¹³C value, such as massspectrometry or off-axis integrated-cavity output spectroscopy (off-axisICOS). Any mass-discerning technique sensitive enough to measure theamounts of carbon, can be used to find ratios of the ¹³C to ¹²C isotopeconcentrations. The δ¹³C values can be measured by the differences inthe energies in the carbon-oxygen double bonds made by the ¹²C and ¹³Cisotopes in carbon dioxide. The δ¹³C value of a carbonate may serve as afingerprint for a CO₂ gas source, as the value can vary from source tosource. In some embodiments, the amount of carbon in the vaterite and/orpolymorphs in the compositions of the invention, may be determined anysuitable technique known in the art. Such techniques include, but arenot limited to, coulometry.

In some embodiments of the foregoing aspects and the foregoingembodiments, the composition has a δ¹³C of less than −12‰; or less than−13‰; or less than −14‰; or less than −15‰; or less than −16‰; or lessthan −17‰; or less than −18‰; or less than −19‰; or less than −20‰; orless than −21‰; or less than −22‰; or less than −25‰; or less than −30‰;or less than −40‰; or less than −50‰; or less than −60‰; or less than−70‰; or less than −80‰; or less than −90‰; or less than −100‰; or from−12‰ to −80‰; or from −12‰ to −70‰; or from −12‰ to −60‰; or from −12‰to −50‰; or from −12‰ to −45‰; or from −12‰ to −40‰; or from −12‰ to−35‰; or from −12‰ to −30‰; or from −12‰ to −25‰; or from −12‰ to −20‰;or from −12‰ to −15‰; or from −13‰ to −80‰; or from −13‰ to −70‰; orfrom −13‰ to −60‰; or from −13‰ to −50‰; or from −13‰ to −45‰; or from−13‰ to −40‰; or from −13‰ to −35‰; or from −13‰ to −30‰; or from −13‰to −25‰; or from −13‰ to −20‰; or from −13‰ to −15‰; from −14‰ to −80‰;or from −14‰ to −70‰; or from −14‰ to −60‰; or from −14‰ to −50‰; orfrom −14‰ to −45‰; or from −14‰ to −40‰; or from −14‰ to −35‰; or from−14‰ to −30‰; or from −14‰ to −25‰; or from −14‰ to −20‰; or from −14‰to −15‰; or from −15‰ to −80‰; or from −15‰ to −70‰; or from −15‰ to−60‰; or from −15‰ to −50‰; or from −15‰ to −45‰; or from −15‰ to −40‰;or from −15‰ to −35‰; or from −15‰ to −30‰; or from −15‰ to −25‰; orfrom −15‰ to −20‰; or from −16‰ to −80‰; or from −16‰ to −70‰; or from−16‰ to −60‰; or from −16‰ to −50‰; or from −16‰ to −45‰; or from −16‰to −40‰; or from −16‰ to −35‰; or from −16‰ to −30‰; or from −16‰ to−25‰; or from −16‰ to −20‰; or from −20‰ to −80‰; or from −20‰ to −70‰;or from −20‰ to −60‰; or from −20‰ to −50‰; or from −20‰ to −40‰; orfrom −20‰ to −35‰; or from −20‰ to −30‰; or from −20‰ to −25‰; or from−30‰ to −80‰; or from −30‰ to −70‰; or from −30‰ to −60‰; or from −30‰to −50‰; or from −30‰ to −40‰; or from −40‰ to −80‰; or from −40‰ to−70‰; or from −40‰ to −60‰; or from −40‰ to −50‰; or from −50‰ to −80‰;or from −50‰ to −70‰; or from −50‰ to −60‰; or from −60‰ to −80‰; orfrom −60‰ to −70‰; or from −70‰ to −80‰; or −12‰; or −13‰; or −14‰; or−15‰; or −16‰; or −17‰; or −18‰; or −19‰; or −20‰; or −21‰; or −22‰; or−25‰; or −30‰; or −40‰; or −50‰; or −60‰; or −70‰; or −80‰; or −90‰; or−100‰.

In some embodiments of the compositions provided herein, the compositionfurther includes a polymorph including, but not limited to, amorphouscalcium carbonate, aragonite, calcite, ikaite, a precursor phase ofvaterite, a precursor phase of aragonite, an intermediary phase that isless stable than calcite, polymorphic forms in between these polymorphs,and combination thereof. It is to be understood that the composition mayalso include any other polymorphic form of calcium carbonate and suchpolymorphic forms are well within the scope of the invention. Someembodiments of the composition provided herein include vaterite orvaterite in combination with other polymorphs, are as shown below inTable III.

TABLE III Composition Vaterite ACC Aragonite Calcite Ikaite 1 x 2 x x 3x x x 4 x x x x 5 x x x x x 6 x x 7 x x x 8 x x x x 9 x x x 10 x x 11 xx x 12 x x x 13 x x x 14 x x x x 15 x x x x 16 x x 17 x x x 18 x x x 19x x x 20 x x x x 21 x x x x 22 x x x x

In some embodiments, the vaterite and the one or more polymorphs, in thecompositions provided herein, are in a vaterite:one or more polymorphratio of greater than 1:1; or a ratio of greater than 2:1; or a ratio ofgreater than 3:1; or a ratio of greater than 4:1; or a ratio of greaterthan 5:1; or a ratio of greater than 6:1; or a ratio of greater than7:1; or a ratio of greater than 8:1; or a ratio of greater than 9:1; ora ratio of greater than 10:1; or a ratio of greater than 11:1; or aratio of greater than 12:1; or a ratio of greater than 13:1; or a ratioof greater than 14:1; or a ratio of greater than 15:1; or a ratio ofgreater than 16:1; or a ratio of greater than 17:1; or a ratio ofgreater than 18:1; or a ratio of greater than 19:1; or a ratio ofgreater than 20:1; or a ratio of 1:1 to 20:1; or a ratio of 1:1 to 18:1;or a ratio of 1:1 to 15:1; or a ratio of 1:1 to 10:1; or a ratio of 1:1to 9:1; or a ratio of 1:1 to 8:1; or a ratio of 1:1 to 7:1; or a ratioof 1:1 to 6:1; or a ratio of 1:1 to 5:1; or a ratio of 1:1 to 4:1; or aratio of 1:1 to 3:1; or a ratio of 1:1 to 2:1; or a ratio of 2:1 to20:1; or a ratio of 2:1 to 15:1; or a ratio of 2:1 to 10:1; or a ratioof 2:1 to 9:1; or a ratio of 2:1 to 8:1; or a ratio of 2:1 to 7:1; or aratio of 2:1 to 6:1; or a ratio of 2:1 to 5:1; or a ratio of 2:1 to 4:1;or a ratio of 2:1 to 3:1; or a ratio of 5:1 to 20:1; or a ratio of 5:1to 15:1; or a ratio of 5:1 to 10:1; or a ratio of 5:1 to 8:1; or a ratioof 7:1 to 20:1; or a ratio of 7:1 to 15:1; or a ratio of 7:1 to 10:1; ora ratio of 7:1 to 9:1; or a ratio of 10:1 to 20:1; or a ratio of 10:1 to15:1; or a ratio of 10:1 to 12:1; or a ratio of 15:1 to 20:1; or a ratioof 15:1 to 18:1; or a ratio of 1:1; or a ratio of 2:1; or a ratio of3:1; or a ratio of 4:1; or a ratio of 5:1; or a ratio of 6:1; or a ratioof 7:1; or a ratio of 8:1; or a ratio of 9:1; or a ratio of 10:1; or aratio of 11:1; or a ratio of 12:1; or a ratio of 13:1; or a ratio of14:1; or a ratio of 15:1; or a ratio of 16:1; or a ratio of 17:1; or aratio of 18:1; or a ratio of 19:1; or a ratio of 20:1.

In some embodiments, the vaterite and the polymorph in the compositionsprovided herein are in a vaterite:one or more polymorph ratio of lessthan 1:1; or 0.1:1; or 0.2:1; or 0.3:1; or 0.4:1; or 0.5:1; or 0.6:1; or0.7:1; or 0.8:1; or 0.9:1; or 0.1:1-10:1; or 0.2:1-10:1; or 0.3:1-10:1;or 0.4:1-10:1; or 0.5:1-10:1; or 0.6:1-10:1; or 0.7:1-10:1; or0.8:1-10:1; or 0.9:1-10:1.

In some embodiments of all of the above recited aspects and embodiments,the composition further includes 1% w/w to 85% w/w aragonite, 1% w/w to85% w/w calcite, 1% w/w to 85% w/w ikaite, or combination thereof.

In some embodiments, the compositions in the above recited aspects andembodiments, further include at least 1% w/w ACC and at least 1% w/waragonite; at least 1% w/w ACC and at least 1% w/w calcite; at least 1%w/w ACC and at least 1% w/w ikaite; at least 1% w/w aragonite and atleast 1% w/w calcite; at least 1% w/w aragonite and at least 1% w/wikaite; at least 1% w/w calcite and at least 1% w/w ikaite; at least 1%w/w ACC, at least 1% w/w aragonite, and at least 1% w/w calcite; atleast 1% w/w ACC, at least 1% w/w aragonite, and at least 1% w/w ikaite;at least 1% w/w ACC, at least 1% w/w ikaite, and at least 1% w/wcalcite; at least 1% w/w aragonite, at least 1% w/w calcite, and atleast 1% w/w ikaite; at least 1% w/w ACC, at least 1% w/w aragonite, atleast 1% w/w calcite, and at least 1% w/w ikaite.

In some embodiments, the compositions in the above recited aspects andembodiments, further includes at least 1% w/w to 90% w/w ACC and atleast 1% w/w to 85% w/w aragonite; at least 1% w/w to 90% w/w ACC and atleast 1% w/w to 85% w/w calcite; at least 1% w/w to 90% w/w ACC and atleast 1% w/w to 85% w/w ikaite; at least 1% w/w to 85% w/w aragonite andat least 1% w/w to 85% w/w calcite; at least 1% w/w to 85% w/w aragoniteand at least 1% w/w to 85% w/w ikaite; at least 1% w/w to 85% w/wcalcite and at least 1% w/w to 85% w/w ikaite; at least 1% w/w to 90%w/w ACC, at least 1% w/w to 85% w/w aragonite, and at least 1% w/w to85% w/w calcite; at least 1% w/w to 90% w/w ACC, at least 1% w/w to 85%w/w aragonite, and at least 1% w/w to 85% w/w ikaite; at least 1% w/w to90% w/w ACC, at least 1% w/w to 85% w/w ikaite, and at least 1% w/w to85% w/w calcite; at least 1% w/w to 85% w/w aragonite, at least 1% w/wto 85% w/w calcite, and at least 1% w/w to 85% w/w ikaite; at least 1%w/w to 90% w/w ACC, at least 1% w/w to 85% w/w aragonite, at least 1%w/w to 85% w/w calcite, and at least 1% w/w to 85% w/w ikaite.

In some embodiments of all of the above recited aspects and embodiments,the compositions further includes at least 1% w/w aragonite; or at least2% w/w aragonite; or at least 5% w/w aragonite; or at least 10% w/waragonite; or at least 20% w/w aragonite; or at least 30% w/w aragonite;or at least 40% w/w aragonite; or at least 50% w/w aragonite; or atleast 60% w/w aragonite; or at least 70% w/w aragonite; or at least 80%w/w aragonite; or at least 85% w/w aragonite; or from 1% w/w to 85% w/waragonite; or from 1% w/w to 80% w/w aragonite; or from 1% w/w to 70%w/w aragonite; or from 1% w/w to 60% w/w aragonite; or from 1% w/w to50% w/w aragonite; or from 1% w/w to 40% w/w aragonite; or from 1% w/wto 30% w/w aragonite; or from 1% w/w to 20% w/w aragonite; or from 1%w/w to 10% w/w aragonite; or from 5% w/w to 85% w/w aragonite; or from5% w/w to 80% w/w aragonite; or from 5% w/w to 70% w/w aragonite; orfrom 5% w/w to 60% w/w aragonite; or from 5% w/w to 50% w/w aragonite;or from 5% w/w to 40% w/w aragonite; or from 5% w/w to 30% w/waragonite; or from 5% w/w to 20% w/w aragonite; or from 5% w/w to 10%w/w aragonite; or from 10% w/w to 85% w/w aragonite; or from 10% w/w to80% w/w aragonite; or from 10% w/w to 70% w/w aragonite; or from 10% w/wto 60% w/w aragonite; or from 10% w/w to 50% w/w aragonite; or from 10%w/w to 40% w/w aragonite; or from 10% w/w to 30% w/w aragonite; or from10% w/w to 20% w/w aragonite; or from 20% w/w to 85% w/w aragonite; orfrom 20% w/w to 80% w/w aragonite; or from 20% w/w to 70% w/w aragonite;or from 20% w/w to 60% w/w aragonite; or from 20% w/w to 50% w/waragonite; or from 20% w/w to 40% w/w aragonite; or from 20% w/w to 30%w/w aragonite; or from 30% w/w to 85% w/w aragonite; or from 30% w/w to80% w/w aragonite; or from 30% w/w to 70% w/w aragonite; or from 30% w/wto 60% w/w aragonite; or from 30% w/w to 50% w/w aragonite; or from 30%w/w to 40% w/w aragonite; or from 40% w/w to 85% w/w aragonite; or from40% w/w to 80% w/w aragonite; or from 40% w/w to 70% w/w aragonite; orfrom 40% w/w to 60% w/w aragonite; or from 40% w/w to 50% w/w aragonite;or from 50% w/w to 85% w/w aragonite; or from 50% w/w to 80% w/waragonite; or from 50% w/w to 70% w/w aragonite; or from 50% w/w to 60%w/w aragonite; or from 60% w/w to 85% w/w aragonite; or from 60% w/w to80% w/w aragonite; or from 60% w/w to 70% w/w aragonite; or from 60% w/wto 65% w/w aragonite; or from 70% w/w to 85% w/w aragonite; or from 70%w/w to 80% w/w aragonite; or from 70% w/w to 75% w/w aragonite; or from80% w/w to 85% w/w aragonite; or 1% w/w aragonite; or 2% w/w aragonite;or 5% w/w aragonite; or 10% w/w aragonite; or 20% w/w aragonite; or 30%w/w aragonite; or 40% w/w aragonite; or 50% w/w aragonite; or 60% w/waragonite; or 70% w/w aragonite; or 80% w/w aragonite; or 85% w/waragonite.

In some embodiments of all of the above recited aspects and embodiments,the compositions further includes at least 1% w/w calcite; or at least2% w/w calcite; or at least 5% w/w calcite; or at least 10% w/w calcite;or at least 20% w/w calcite; or at least 30% w/w calcite; or at least40% w/w calcite; or at least 50% w/w calcite; or at least 60% w/wcalcite; or at least 70% w/w calcite; or at least 80% w/w calcite; or atleast 85% w/w calcite; or from 1% w/w to 85% w/w calcite; or from 1% w/wto 80% w/w calcite; or from 1% w/w to 75% w/w calcite; or from 1% w/w to70% w/w calcite; or from 1% w/w to 65% w/w calcite; or from 1% w/w to60% w/w calcite; or from 1% w/w to 55% w/w calcite; or from 1% w/w to50% w/w calcite; or from 1% w/w to 45% w/w calcite; or from 1% w/w to40% w/w calcite; or from 1% w/w to 35% w/w calcite; or from 1% w/w to30% w/w calcite; or from 1% w/w to 25% w/w calcite; or from 1% w/w to20% w/w calcite; or from 1% w/w to 15% w/w calcite; or from 1% w/w to10% w/w calcite; or from 5% w/w to 85% w/w calcite; or from 5% w/w to80% w/w calcite; or from 5% w/w to 70% w/w calcite; or from 5% w/w to60% w/w calcite; or from 5% w/w to 50% w/w calcite; or from 5% w/w to40% w/w calcite; or from 5% w/w to 30% w/w calcite; or from 5% w/w to20% w/w calcite; or from 5% w/w to 10% w/w calcite; or from 10% w/w to85% w/w calcite; or from 10% w/w to 80% w/w calcite; or from 10% w/w to70% w/w calcite; or from 10% w/w to 60% w/w calcite; or from 10% w/w to50% w/w calcite; or from 10% w/w to 40% w/w calcite; or from 10% w/w to30% w/w calcite; or from 10% w/w to 20% w/w calcite; or from 20% w/w to85% w/w calcite; or from 20% w/w to 80% w/w calcite; or from 20% w/w to70% w/w calcite; or from 20% w/w to 60% w/w calcite; or from 20% w/w to50% w/w calcite; or from 20% w/w to 40% w/w calcite; or from 20% w/w to30% w/w calcite; or from 30% w/w to 85% w/w calcite; or from 30% w/w to80% w/w calcite; or from 30% w/w to 70% w/w calcite; or from 30% w/w to60% w/w calcite; or from 30% w/w to 50% w/w calcite; or from 30% w/w to40% w/w calcite; or from 40% w/w to 85% w/w calcite; or from 40% w/w to80% w/w calcite; or from 40% w/w to 70% w/w calcite; or from 40% w/w to60% w/w calcite; or from 40% w/w to 50% w/w calcite; or from 50% w/w to85% w/w calcite; or from 50% w/w to 80% w/w calcite; or from 50% w/w to70% w/w calcite; or from 50% w/w to 60% w/w calcite; or from 60% w/w to85% w/w calcite; or from 60% w/w to 80% w/w calcite; or from 60% w/w to70% w/w calcite; or from 60% w/w to 65% w/w calcite; or from 70% w/w to85% w/w calcite; or from 70% w/w to 80% w/w calcite; or from 70% w/w to75% w/w calcite; or from 80% w/w to 85% w/w calcite; or 1% w/w calcite;or 2% w/w calcite; or 5% w/w calcite; or 10% w/w calcite; or 20% w/wcalcite; or 30% w/w calcite; or 40% w/w calcite; or 50% w/w calcite; or60% w/w calcite; or 70% w/w calcite; or 80% w/w calcite; or 85% w/wcalcite.

In some embodiments of all of the above recited aspects and embodiments,the compositions further includes at least 1% w/w ikaite; or at least 2%w/w ikaite; or at least 5% w/w ikaite; or at least 10% w/w ikaite; or atleast 20% w/w ikaite; or at least 30% w/w ikaite; or at least 40% w/wikaite; or at least 50% w/w ikaite; or at least 60% w/w ikaite; or atleast 70% w/w ikaite; or at least 80% w/w ikaite; or at least 85% w/wikaite; or from 1% w/w to 85% w/w ikaite; or from 1% w/w to 80% w/wikaite; or from 1% w/w to 70% w/w ikaite; or from 1% w/w to 60% w/wikaite; or from 1% w/w to 50% w/w ikaite; or from 1% w/w to 40% w/wikaite; or from 1% w/w to 30% w/w ikaite; or from 1% w/w to 20% w/wikaite; or from 1% w/w to 10% w/w ikaite; or from 5% w/w to 85% w/wikaite; or from 5% w/w to 80% w/w ikaite; or from 5% w/w to 70% w/wikaite; or from 5% w/w to 60% w/w ikaite; or from 5% w/w to 50% w/wikaite; or from 5% w/w to 40% w/w ikaite; or from 5% w/w to 30% w/wikaite; or from 5% w/w to 20% w/w ikaite; or from 5% w/w to 10% w/wikaite; or from 10% w/w to 85% w/w ikaite; or from 10% w/w to 80% w/wikaite; or from 10% w/w to 70% w/w ikaite; or from 10% w/w to 60% w/wikaite; or from 10% w/w to 50% w/w ikaite; or from 10% w/w to 40% w/wikaite; or from 10% w/w to 30% w/w ikaite; or from 10% w/w to 20% w/wikaite; or from 20% w/w to 85% w/w ikaite; or from 20% w/w to 80% w/wikaite; or from 20% w/w to 70% w/w ikaite; or from 20% w/w to 60% w/wikaite; or from 20% w/w to 50% w/w ikaite; or from 20% w/w to 40% w/wikaite; or from 20% w/w to 30% w/w ikaite; or from 30% w/w to 85% w/wikaite; or from 30% w/w to 80% w/w ikaite; or from 30% w/w to 70% w/wikaite; or from 30% w/w to 60% w/w ikaite; or from 30% w/w to 50% w/wikaite; or from 30% w/w to 40% w/w ikaite; or from 40% w/w to 85% w/wikaite; or from 40% w/w to 80% w/w ikaite; or from 40% w/w to 70% w/wikaite; or from 40% w/w to 60% w/w ikaite; or from 40% w/w to 50% w/wikaite; or from 50% w/w to 85% w/w ikaite; or from 50% w/w to 80% w/wikaite; or from 50% w/w to 70% w/w ikaite; or from 50% w/w to 60% w/wikaite; or from 60% w/w to 85% w/w ikaite; or from 60% w/w to 80% w/wikaite; or from 60% w/w to 70% w/w ikaite; or from 60% w/w to 65% w/wikaite; or from 70% w/w to 85% w/w ikaite; or from 70% w/w to 80% w/wikaite; or from 70% w/w to 75% w/w ikaite; or from 80% w/w to 85% w/wikaite; or 1% w/w ikaite; or 2% w/w ikaite; or 5% w/w ikaite; or 10% w/wikaite; or 20% w/w ikaite; or 30% w/w ikaite; or 40% w/w ikaite; or 50%w/w ikaite; or 60% w/w ikaite; or 70% w/w ikaite; or 80% w/w ikaite; or85% w/w ikaite.

The compositions of the invention may include a number of differentcations, such as, but are not limited to, calcium, magnesium, sodium,potassium, sulfur, boron, silicon, strontium, and combinations thereof,where carbonate minerals include, but are not limited to: calciumcarbonate minerals, magnesium carbonate minerals and calcium magnesiumcarbonate minerals. Calcium carbonate minerals in the composition of theinvention include, but are not limited to: vaterite alone or incombination with calcite, aragonite, ikaite, amorphous calciumcarbonate, a precursor phase of vaterite, a precursor phase ofaragonite, an intermediary phase that is less stable than calcite,polymorphic forms in between these polymorphs, or combination thereof.These carbonate minerals may also be present in combination withmagnesium carbonate minerals. Magnesium carbonate minerals include, butare not limited to, magnesite (MgCO₃), barringtonite (MgCO₃.2H₂O),nesquehonite (MgCO₃.3H₂O), lanfordite (MgCO₃.5H₂O) and amorphousmagnesium calcium carbonate (MgCO₃.nH₂O). The carbonate minerals in thecomposition of the invention may also be present in combination withcalcium magnesium carbonate minerals which include, but are not limitedto, dolomite (CaMgCO₃), huntitte (CaMg(CO₃)₄) and sergeevite(Ca₂Mg₁₁(CO₃)₁₃.H₂O). Other calcium mineral that may be present in thecomposition of the invention, is portlandite (Ca(OH)₂), and amorphoushydrated analogs thereof. Other magnesium mineral that may be present inthe composition of the invention, is brucite (Mg(OH)₂), and amorphoushydrated analogs thereof.

In some embodiments of all of the above recited aspects and embodiments,the composition further includes strontium (Sr). In some embodiments,the Sr is present in the composition in an amount of 1-50,000 parts permillion (ppm); or 1-10,000 ppm; or 1-5,000 ppm; or 1-1,000 ppm; or3-50,000 ppm; or 3-10,000 ppm; or 3-9,000 ppm; or 3-8,000 ppm; or3-7,000 ppm; or 3-6,000 ppm; or 3-5,000 ppm; or 3-4,000 ppm; or 3-3,000ppm; or 3-2,000 ppm; or 3-1,000 ppm; or 3-900 ppm; or 3-800 ppm; or3-700 ppm; or 3-600 ppm; or 3-500 ppm; or 3-400 ppm; or 3-300 ppm; or3-200 ppm; or 3-100 ppm; or 3-50 ppm; or 3-10 ppm; or 10-50,000 ppm; or10-10,000 ppm; or 10-9,000 ppm; or 10-8,000 ppm; or 10-7,000 ppm; or10-6,000 ppm; or 10-5,000 ppm; or 10-4,000 ppm; or 10-3,000 ppm; or10-2,000 ppm; or 10-1,000 ppm; or 10-900 ppm; or 10-800 ppm; or 10-700ppm; or 10-600 ppm; or 10-500 ppm; or 10-400 ppm; or 10-300 ppm; or10-200 ppm; or 10-100 ppm; or 10-50 ppm; or 100-50,000 ppm; or100-10,000 ppm; or 100-9,000 ppm; or 100-8,000 ppm; or 100-7,000 ppm; or100-6,000 ppm; or 100-5,000 ppm; or 100-4,000 ppm; or 100-3,000 ppm; or100-2,000 ppm; or 100-1,000 ppm; or 100-900 ppm; or 100-800 ppm; or100-700 ppm; or 100-600 ppm; or 100-500 ppm; or 100-400 ppm; or 100-300ppm; or 100-200 ppm; or 200-50,000 ppm; or 200-10,000 ppm; or 200-1,000ppm; or 200-500 ppm; or 500-50,000 ppm; or 500-10,000 ppm; or 500-1,000ppm; or 10 ppm; or 100 ppm; or 200 ppm; or 500 ppm; or 1000 ppm; or 5000ppm; or 8000 ppm; or 10,000 ppm.

In some embodiments, the above recited Sr is present in a crystallattice of the vaterite. In some embodiments, the above recited Sr ispresent in a crystal lattice of the aragonite. In some embodiments, theabove recited Sr is present in a crystal lattice of the calcite. In someembodiments, the above recited Sr is present in a crystal lattice of theikaite. In some embodiments, the above recited Sr is present in acrystal lattice of one or more of vaterite, aragonite, calcite, andikaite.

The water employed in the invention may be fresh water, saltwater, or analkaline-earth-metal-containing water, depending on the method employingthe water. In some embodiments, the water employed in the processincludes one or more alkaline earth metals, e.g., magnesium, calcium,etc. The various types of water that may be employed in the inventionare described below. In some embodiments, the water contains calcium inamounts ranging from 50 to 20,000 ppm; or 50 to 10,000 ppm; or 50 to5,000 ppm; or 50 to 1,000 ppm; or 50 to 500 ppm; or 50 to 100 ppm; or100 to 20,000 ppm; or 100 to 10,000 ppm; or 100 to 5,000 ppm; or 100 to1,000 ppm; or 100 to 500 ppm; or 500 to 20,000 ppm; or 500 to 10,000ppm; or 500 to 5,000 ppm; or 500 to 1,000 ppm; or 1,000 to 20,000 ppm;or 1,000 to 10,000 ppm; or 1,000 to 5,000 ppm; or 5,000 to 20,000 ppm;or 5,000 to 10,000 ppm; or 10,000 to 20,000 ppm.

In some embodiments, the water contains magnesium in amounts rangingfrom 50 to 20,000 ppm; or 50 to 10,000 ppm; or 50 to 5,000 ppm; or 50 to1,000 ppm; or 50 to 500 ppm; or 50 to 100 ppm; or 100 to 20,000 ppm; or100 to 10,000 ppm; or 100 to 5,000 ppm; or 100 to 1,000 ppm; or 100 to500 ppm; or 500 to 20,000 ppm; or 500 to 10,000 ppm; or 500 to 5,000ppm; or 500 to 1,000 ppm; or 1,000 to 20,000 ppm; or 1,000 to 10,000ppm; or 1,000 to 5,000 ppm; or 5,000 to 20,000 ppm; or 5,000 to 10,000ppm; or 10,000 to 20,000 ppm.

The composition has, in certain embodiments, a calcium/magnesium ratiothat is influenced by, and therefore reflects, the water source fromwhich it has been precipitated, e.g., seawater, which contains moremagnesium than calcium, or, e.g., certain brines, which often containone-hundred-fold the calcium content as seawater; the calcium/magnesiumratio also reflects factors such as the addition of calcium and/ormagnesium-containing substances during the production process, e.g., theuse of flyash, red mud, slag, or other calcium and/ormagnesium-containing industrial wastes, or the use of calcium and/ormagnesium-containing minerals such as mafic and ultramafic minerals,such as serpentine, olivine, and the like. Because of the largevariation in raw materials as well as materials added during production,the calcium/magnesium molar ratio may vary widely in various embodimentsof the compositions and methods of the invention, and indeed in certainembodiment the ratio may be adjusted according to the intended use ofthe composition.

In some embodiments of all of the above recited aspects and embodiments,the composition further includes magnesium (Mg). In some embodiments, Mgis present as magnesium carbonate. In some embodiments, a ratio ofcalcium to magnesium (Ca:Mg) or the ratio of vaterite:magnesiumcarbonate is greater than 1:1; or a ratio of greater than 2:1; or aratio of greater than 3:1; or a ratio of greater than 4:1; or a ratio ofgreater than 5:1; or a ratio of greater than 6:1; or a ratio of greaterthan 7:1; or a ratio of greater than 8:1; or a ratio of greater than9:1; or a ratio of greater than 10:1; or a ratio of greater than 15:1;or a ratio of greater than 20:1; or a ratio of greater than 30:1; or aratio of greater than 40:1; or a ratio of greater than 50:1; or a ratioof greater than 60:1; or a ratio of greater than 70:1; or a ratio ofgreater than 80:1; or a ratio of greater than 90:1; or a ratio ofgreater than 100:1; or a ratio of greater than 150:1; or a ratio ofgreater than 200:1; or a ratio of greater than 250:1; or a ratio ofgreater than 300:1; or a ratio of greater than 350:1; or a ratio ofgreater than 400:1; or a ratio of greater than 450:1; or a ratio ofgreater than 500:1; or a ratio of 1:1 to 500:1; or a ratio of 1:1 to450:1; or a ratio of 1:1 to 400:1; or a ratio of 1:1 to 350:1; or aratio of 1:1 to 300:1; or a ratio of 1:1 to 250:1; or a ratio of 1:1 to200:1; or a ratio of 1:1 to 150:1; or a ratio of 1:1 to 100:1; or aratio of 1:1 to 50:1; or a ratio of 1:1 to 25:1; or a ratio of 1:1 to10:1; or a ratio of 5:1 to 500:1; or a ratio of 5:1 to 450:1; or a ratioof 5:1 to 400:1; or a ratio of 5:1 to 350:1; or a ratio of 5:1 to 300:1;or a ratio of 5:1 to 250:1; or a ratio of 5:1 to 200:1; or a ratio of5:1 to 150:1; or a ratio of 5:1 to 100:1; or a ratio of 5:1 to 50:1; ora ratio of 5:1 to 25:1; or a ratio of 5:1 to 10:1; or a ratio of 10:1 to500:1; or a ration of 10:1 to 450:1; or a ratio of 10:1 to 400:1; or aratio of 10:1 to 350:1; or a ratio of 10:1 to 300:1; or a ratio of 10:1to 250:1; or a ratio of 10:1 to 200:1; or a ratio of 10:1 to 150:1; or aratio of 10:1 to 100:1; or a ratio of 10:1 to 50:1; or a ratio of 10:1to 25:1; or a ratio of 20:1 to 500:1; or a ratio of 20:1 to 450:1; or aratio of 20:1 to 400:1; or a ratio of 20:1 to 350:1; or a ratio of 20:1to 300:1; or a ratio of 20:1 to 250:1; or a ratio of 20:1 to 200:1; or aratio of 20:1 to 150:1; or a ratio of 20:1 to 100:1; or a ratio of 20:1to 50:1; or a ratio of 20:1 to 25:1; or a ratio of 50:1 to 500:1; or aratio of 50:1 to 450:1; or a ratio of 50:1 to 400:1; or a ratio of 50:1to 350:1; or a ratio of 50:1 to 300:1; or a ratio of 50:1 to 250:1; or aratio of 50:1 to 200:1; or a ratio of 50:1 to 150:1; or a ratio of 50:1to 100:1; or a ratio of 100:1 to 500:1; or a ratio of 100:1 to 450:1; ora ratio of 100:1 to 400:1; or a ratio of 100:1 to 350:1; or a ratio of100:1 to 300:1; or a ratio of 100:1 to 250:1; or a ratio of 100:1 to200:1; or a ratio of 100:1 to 150:1; or a ratio of 200:1 to 500:1; or aratio of 200:1 to 450:1; or a ratio of 200:1 to 400:1; or a ratio of200:1 to 350:1; or a ratio of 200:1 to 300:1; or a ratio of 200:1 to250:1; or a ratio of 300:1 to 500:1; or a ratio of 300:1 to 450:1; or aratio of 300:1 to 400:1; or a ratio of 300:1 to 350:1; or a ratio of400:1 to 500:1; or a ratio of 400:1 to 450:1; or a ratio of 1:1; or aratio of 2:1; or a ratio of 3:1; or a ratio of 4:1; or a ratio of 5:1;or a ratio of 6:1; or a ratio of 7:1; or a ratio of 8:1; or a ratio of9:1; or a ratio of 10:1; or a ratio of 11:1; or a ratio of 15:1; or aratio of 20:1; or a ratio of 30:1; or a ratio of 40:1; or a ratio of50:1; or a ratio of 60:1; or a ratio of 70:1; or a ratio of 80:1; or aratio of 90:1; or a ratio of 100:1; or a ratio of 150:1; or a ratio of200:1; or a ratio of 250:1; or a ratio of 300:1; or a ratio of 350:1; ora ratio of 400:1; or a ratio of 450:1; or a ratio of 500:1. In someembodiments, the ratio of calcium to magnesium (Ca:Mg) is between 2:1 to5:1, or greater than 4:1, or 4:1. In some embodiments, the ratios hereinare molar ratios or weight (such as, grams, mg or ppm) ratios.

In some embodiments, a ratio of magnesium to calcium (Mg:Ca) or theratio of magnesium carbonate:vaterite is between 1:1 to 10:1; or between2:1 to 10:1; or between 3:1 to 10:1; or between 4:1 to 10:1; or between5:1 to 10:1; or between 6:1 to 10:1; or between 7:1 to 10:1; or between8:1 to 10:1; or between 9:1 to 10:1.

In some embodiments, the amount of Mg present in the compositionsprovided herein is less than 2% w/w; or less than 1.5% w/w; or less than1% w/w; or less than 0.5% w/w; or less than 0.1% w/w; or between 0.1%w/w Mg to 5% w/w Mg; or between 0.1% w/w Mg to 2% w/w Mg; or between0.1% w/w Mg to 1.5% w/w Mg; or between 0.1% w/w Mg to 1% w/w Mg; orbetween 0.1% w/w Mg to 0.5% w/w Mg.

Alternatively, in some embodiments, the ratio of calcium to magnesium(Ca:Mg) is 0.1; or 0.2; or 0.3; or 0.4; or 0.5.

In some embodiments, the compositions provided herein further includesodium. In such compositions the sodium is present in an amount lessthan 100,000 ppm; or less than 80,000 ppm; or less than 50,000 ppm; orless than 20,000 ppm; or less than 15,000 ppm; or less than 10,000 ppm;or less than 5,000 ppm; or less than 1,000 ppm; or less than 500 ppm; orless than 400 ppm; or less than 300 ppm; or less than 200 ppm; or lessthan 100 ppm; or between 100 ppm to 100,000 ppm; or between 100 ppm to50,000 ppm; or between 100 ppm to 30,000 ppm; or between 100 ppm to20,000 ppm; or between 100 ppm to 15,000 ppm; or between 100 ppm to10,000 ppm; or between 100 ppm to 5,000 ppm; or between 100 ppm to 1,000ppm; or between 100 ppm to 500 ppm; or between 100 ppm to 400 ppm; orbetween 100 ppm to 300 ppm; or between 100 ppm to 200 ppm; or between500 ppm to 100,000 ppm; or between 500 ppm to 50,000 ppm; or between 500ppm to 30,000 ppm; or between 500 ppm to 20,000 ppm; or between 500 ppmto 15,000 ppm; or between 500 ppm to 10,000 ppm; or between 500 ppm to5,000 ppm; or between 500 ppm to 1,000 ppm; or between 1000 ppm to100,000 ppm; or between 1000 ppm to 50,000 ppm; or between 1000 ppm to30,000 ppm; or between 1000 ppm to 20,000 ppm; or between 1000 ppm to15,000 ppm; or between 1000 ppm to 10,000 ppm; or between 1000 ppm to5,000 ppm; or between 5000 ppm to 100,000 ppm; or between 5000 ppm to50,000 ppm; or between 10,000 ppm to 100,000 ppm; or between 10,000 ppmto 50,000 ppm; or between 50,000 ppm to 100,000 ppm; or 20,000 ppm; or15,000 ppm; or 10,000 ppm; or 5,000 ppm; or 1,000 ppm; or 500 ppm; or400 ppm; or 300 ppm; or 200 ppm; or 100 ppm.

In some embodiments, the compositions of the invention do not includecalcium phosphate. In some embodiments, the compositions of theinvention include calcium phosphate. In such compositions, the calciumphosphate is in an amount of less than 20,000 ppm; or less than 15,000ppm; or less than 10,000 ppm; or less than 5,000 ppm; or less than 1,000ppm; or less than 500 ppm; or less than 400 ppm; or less than 300 ppm;or less than 200 ppm; or less than 100 ppm; or between 100 ppm to 20,000ppm; or between 100 ppm to 15,000 ppm; or between 100 ppm to 10,000 ppm;or between 100 ppm to 5,000 ppm; or between 100 ppm to 1,000 ppm; orbetween 100 ppm to 500 ppm; or between 100 ppm to 400 ppm; or between100 ppm to 300 ppm; or between 100 ppm to 200 ppm; or 20,000 ppm; or15,000 ppm; or 10,000 ppm; or 5,000 ppm; or 1,000 ppm; or 500 ppm; or400 ppm; or 300 ppm; or 200 ppm; or 100 ppm.

In some embodiments, the composition provided herein is a particulatecomposition with an average particle size of 0.1-100 microns. Theaverage particle size may be determined using any conventional particlesize determination method, such as, but is not limited to,multi-detector laser scattering or sieving (i.e. <38 microns). Incertain embodiments, unimodel or multimodal, e.g., bimodal or other,distributions are present. Bimodal distributions allow the surface areato be minimized, thus allowing a lower liquids/solids mass ratio for thecement yet providing smaller reactive particles for early reaction. Insuch instances, the average particle size of the larger size class canbe upwards of 1000 microns (1 mm). In some embodiments, the compositionprovided herein is a particulate composition with an average particlesize of 0.1-1000 microns; or 0.1-900 microns; or 0.1-800 microns; or0.1-700 microns; or 0.1-600 microns; or 0.1-500 microns; or 0.1-400microns; or 0.1-300 microns; or 0.1-200 microns; or 0.1-100 microns; or0.1-90 microns; or 0.1-80 microns; or 0.1-70 microns; or 0.1-60 microns;or 0.1-50 microns; or 0.1-40 microns; or 0.1-30 microns; or 0.1-20microns; or 0.1-10 microns; or 0.1-5 microns; or 0.5-100 microns; or0.5-90 microns; or 0.5-80 microns; or 0.5-70 microns; or 0.5-60 microns;or 0.5-50 microns; or 0.5-40 microns; or 0.5-30 microns; or 0.5-20microns; or 0.5-10 microns; or 0.5-5 microns; or 1-100 microns; or 1-90microns; or 1-80 microns; or 1-70 microns; or 1-60 microns; or 1-50microns; or 1-40 microns; or 1-30 microns; or 1-20 microns; or 1-10microns; or 1-5 microns; or 3-100 microns; or 3-90 microns; or 3-80microns; or 3-70 microns; or 3-60 microns; or 3-50 microns; or 3-40microns; or 3-30 microns; or 3-20 microns; or 3-10 microns; or 3-8microns; or 5-100 microns; or 5-90 microns; or 5-80 microns; or 5-70microns; or 5-60 microns; or 5-50 microns; or 5-40 microns; or 5-30microns; or 5-20 microns; or 5-10 microns; or 5-8 microns; or 8-100microns; or 8-90 microns; or 8-80 microns; or 8-70 microns; or 8-60microns; or 8-50 microns; or 8-40 microns; or 8-30 microns; or 8-20microns; or 8-10 microns; or 10-100 microns; or 10-90 microns; or 10-80microns; or 10-70 microns; or 10-60 microns; or 10-50 microns; or 10-40microns; or 10-30 microns; or 10-20 microns; or 10-15 microns; or 15-100microns; or 15-90 microns; or 15-80 microns; or 15-70 microns; or 15-60microns; or 15-50 microns; or 15-40 microns; or 15-30 microns; or 15-20microns; or 20-100 microns; or 20-90 microns; or 20-80 microns; or 20-70microns; or 20-60 microns; or 20-50 microns; or 20-40 microns; or 20-30microns; or 30-100 microns; or 30-90 microns; or 30-80 microns; or 30-70microns; or 30-60 microns; or 30-50 microns; or 30-40 microns; or 40-100microns; or 40-90 microns; or 40-80 microns; or 40-70 microns; or 40-60microns; or 40-50 microns; or 50-100 microns; or 50-90 microns; or 50-80microns; or 50-70 microns; or 50-60 microns; or 60-100 microns; or 60-90microns; or 60-80 microns; or 60-70 microns; or 70-100 microns; or 70-90microns; or 70-80 microns; or 80-100 microns; or 80-90 microns; or 0.1microns; or 0.5 microns; or 1 microns; or 2 microns; or 3 microns; or 4microns; or 5 microns; or 8 microns; or 10 microns; or 15 microns; or 20microns; or 30 microns; or 40 microns; or 50 microns; or 60 microns; or70 microns; or 80 microns; or 100 microns. For example, in someembodiments, the composition provided herein is a particulatecomposition with an average particle size of 0.1-20 micron; or 0.1-15micron; or 0.1-10 micron; or 0.1-8 micron; or 0.1-5 micron; or 1-5micron; or 5-10 micron.

In some embodiments, the composition includes one or more differentsizes of the particles in the composition. In some embodiments, thecomposition includes two or more, or three or more, or four or more, orfive or more, or ten or more, or 20 or more, or 3-20, or 4-10 differentsizes of the particles in the composition. For example, the compositionmay include two or more, or three or more, or between 3-20 particlesranging from 0.1-10 micron, 10-50 micron, 50-100 micron, 100-200 micron,200-500 micron, 500-1000 micron, and/or sub-micron sizes of theparticles.

In some embodiments, the composition of the invention may includedifferent morphologies of the particles, such as, but not limited to,fine or disperse and large or agglomerated.

The bulk density of the composition in the powder form or after thesetting and/or hardening of the cement may vary. In some embodiments,the composition provided herein has a bulk density of between 75lb/ft³-170 lb/ft³; or between 75 lb/ft³-160 lb/ft³; or between 75lb/ft³-150 lb/ft³; or between 75 lb/ft³-140 lb/ft³; or between 75lb/ft³-130 lb/ft³; or between 75 lb/ft³-125 lb/ft³; or between 75lb/ft³-120 lb/ft³; or between 75 lb/ft³-110 lb/ft³; or between 75lb/ft³-100 lb/ft³; or between 75 lb/ft³-90 lb/ft³; or between 75lb/ft³-80 lb/ft³; or between 80 lb/ft³-170 lb/ft³; or between 80lb/ft³-160 lb/ft³; or between 80 lb/ft³-150 lb/ft³; or between 80lb/ft³-140 lb/ft³; or between 80 lb/ft³-130 lb/ft³; or between 80lb/ft³-125 lb/ft³; or between 80 lb/ft³-120 lb/ft³; or between 80lb/ft³-110 lb/ft³; or between 80 lb/ft³-100 lb/ft³; or between 80lb/ft³-90 lb/ft³; or between 90 lb/ft³-170 lb/ft³; or between 90lb/ft³-160 lb/ft³; or between 90 lb/ft³-150 lb/ft³; or between 90lb/ft³-140 lb/ft³; or between 90 lb/ft³-130 lb/ft³; or between 90lb/ft³-125 lb/ft³; or between 90 lb/ft³-120 lb/ft³; or between 90lb/ft³-110 lb/ft³; or between 90 lb/ft³-100 lb/ft³; or between 90lb/ft³-90 lb/ft³; or between 100 lb/ft³-170 lb/ft³; or between 100lb/ft³-160 lb/ft³; or between 100 lb/ft³-150 lb/ft³; or between 100lb/ft³-140 lb/ft³; or between 100 lb/ft³-130 lb/ft³; or between 100lb/ft³-125 lb/ft³; or between 100 lb/ft³-120 lb/ft³; or between 100lb/ft³-110 lb/ft³; or between 110 lb/ft³-170 lb/ft³; or between 110lb/ft³-160 lb/ft³; or between 110 lb/ft³-150 lb/ft³; or between 110lb/ft³-140 lb/ft³; or between 110 lb/ft³-130 lb/ft³; or between 110lb/ft³-125 lb/ft³; or between 110 lb/ft³-120 lb/ft³; or between 120lb/ft³-170 lb/ft³; or between 120 lb/ft³-160 lb/ft³; or between 120lb/ft³-150 lb/ft³; or between 120 lb/ft³-140 lb/ft³; or between 120lb/ft³-130 lb/ft³; or between 120 lb/ft³-125 lb/ft³; or between 130lb/ft³-170 lb/ft³; or between 130 lb/ft³-160 lb/ft³; or between 130lb/ft³-150 lb/ft³; or between 130 lb/ft³-140 lb/ft³; or between 140lb/ft³-170 lb/ft³; or between 140 lb/ft³-160 lb/ft³; or between 140lb/ft³-150 lb/ft³; or between 150 lb/ft³-170 lb/ft³; or between 150lb/ft³-160 lb/ft³; or between 160 lb/ft³-170 lb/ft³; or 75 lb/ft³; or 80lb/ft³; or 85 lb/ft³; or 90 lb/ft³; or 95 lb/ft³; or 100 lb/ft³; or 110lb/ft³; or 120 lb/ft³; or 130 lb/ft³; or 140 lb/ft³; or 150 lb/ft³; or160 lb/ft³; or 170 lb/ft³.

The surface area of the components making up the cement may vary. Insome embodiments, the compositions of the invention have an averagesurface area sufficient to provide for a liquid to solids ratio (asdescribed herein) upon combination with a liquid to produce a settablecomposition. In some embodiments, an average surface area ranges from0.5 m²/gm-50 m²/gm. The surface area may be determined using the surfacearea determination protocol described in Breunner, Emmit and Teller(BET) surface area analysis. In some embodiments, the compositionprovided herein has an average surface area of from 0.5 m²/gm-50 m²/gm;or from 0.5 m²/gm-45 m²/gm; or from 0.5 m²/gm-40 m²/gm; or from 0.5m²/gm-35 m²/gm; or from 0.5 m²/gm-30 m²/gm; or from 0.5 m²/gm-25 m²/gm;or from 0.5 m²/gm-20 m²/gm; or from 0.5 m²/gm-15 m²/gm; or from 0.5m²/gm-10 m²/gm; or from 0.5 m²/gm-5 m²/gm; or from 0.5 m²/gm-4 m²/gm; orfrom 0.5 m²/gm-2 m²/gm; or from 0.5 m²/gm-1 m²/gm; or from 1 m²/gm-50m²/gm; or from 1 m²/gm-45 m²/gm; or from 1 m²/gm-40 m²/gm; or from 1m²/gm-35 m²/gm; or from 1 m²/gm-30 m²/gm; or from 1 m²/gm-25 m²/gm; orfrom 1 m²/gm-20 m²/gm; or from 1 m²/gm-15 m²/gm; or from 1 m²/gm-10m²/gm; or from 1 m²/gm-5 m²/gm; or from 1 m²/gm-4 m²/gm; or from 1m²/gm-2 m²/gm; or from 2 m²/gm-50 m²/gm; or from 2 m²/gm-45 m²/gm; orfrom 2 m²/gm-40 m²/gm; or from 2 m²/gm-35 m²/gm; or from 2 m²/gm-30m²/gm; or from 2 m²/gm-25 m²/gm; or from 2 m²/gm-20 m²/gm; or from 2m²/gm-15 m²/gm; or from 2 m²/gm-10 m²/gm; or from 2 m²/gm-5 m²/gm; orfrom 2 m²/gm-4 m²/gm; or from 5 m²/gm-50 m²/gm; or from 5 m²/gm-45m²/gm; or from 5 m²/gm-40 m²/gm; or from 5 m²/gm-35 m²/gm; or from 5m²/gm-30 m²/gm; or from 5 m²/gm-25 m²/gm; or from 5 m²/gm-20 m²/gm; orfrom 5 m²/gm-15 m²/gm; or from 5 m²/gm-10 m²/gm; or from 8 m²/gm-50m²/gm; or from 8 m²/gm-45 m²/gm; or from 8 m²/gm-40 m²/gm; or from 8m²/gm-35 m²/gm; or from 8 m²/gm-30 m²/gm; or from 8 m²/gm-25 m²/gm; orfrom 8 m²/gm-20 m²/gm; or from 8 m²/gm-15 m²/gm; or from 8 m²/gm-10m²/gm; or from 10 m²/gm-50 m²/gm; or from 10 m²/gm-45 m²/gm; or from 10m²/gm-40 m²/gm; or from 10 m²/gm-35 m²/gm; or from 10 m²/gm-30 m²/gm; orfrom 10 m²/gm-25 m²/gm; or from 10 m²/gm-20 m²/gm; or from 10 m²/gm-15m²/gm; or from 15 m²/gm-50 m²/gm; or from 15 m²/gm-45 m²/gm; or from 15m²/gm-40 m²/gm; or from 15 m²/gm-35 m²/gm; or from 15 m²/gm-30 m²/gm; orfrom 15 m²/gm-25 m²/gm; or from 15 m²/gm-20 m²/gm; or from 20 m²/gm-50m²/gm; or from 20 m²/gm-45 m²/gm; or from 20 m²/gm-40 m²/gm; or from 20m²/gm-35 m²/gm; or from 20 m²/gm-30 m²/gm; or from 20 m²/gm-25 m²/gm; orfrom 30 m²/gm-50 m²/gm; or from 30 m²/gm-45 m²/gm; or from 30 m²/gm-40m²/gm; or from 30 m²/gm-35 m²/gm; or from 40 m²/gm-50 m²/gm; or from 40m²/gm-45 m²/gm; or 0.5 m²/gm; or 1 m²/gm; or 2 m²/gm; or 5 m²/gm; or 10m²/gm; or 15 m²/gm; or 20 m²/gm; or 30 m²/gm; or 40 m²/gm; or 50 m²/gm.In some embodiments, the composition of the invention includes a mix ofparticles, such as, but not limited to, two or more, three or more, orfour or more, or 5-10, or 10-20, or 1-20, or 1-50 particles withdifferent surface area.

In some embodiments, in the foregoing aspects and the foregoingembodiments, the composition has a zeta potential of greater than −25millivolts (mV). Zeta potential is the potential difference between thedispersion medium and the stationary layer of fluid attached to thedispersed particle. The zeta potential indicates a degree of repulsionbetween adjacent similar particles in the dispersion. When the zetapotential is high, the particles may repel and resist aggregationresulting in high dispersion of the particles in the medium. When thezeta potential is low, the attraction may exceed repulsion causing thedispersion to break and particles to flocculate. Without being bound byany theory, it is proposed that the high dispersion of the particles inthe compositions of the invention may facilitate the SCM properties ofthe composition where the SCM composition may not flocculate readily andmay be added to Portland cement as SCM. The low dispersion of theparticles in the composition may cause setting and hardening of thecomposition making the cement suitable as the hydraulic cement. The lowdispersion of the particles in the composition may also cause settingand hardening of the composition making the cement suitable as theself-cementing material. The experimental techniques to determine thezeta potential are well known in the art and include, but are notlimited to, electrophoresis such as microelectrophoresis andelectrophoretic light scattering.

In some embodiments, the foregoing aspects and the foregoingembodiments, the composition includes a zeta potential of greater than−20 mV; or greater than −15 mV; or greater than −10 mV; or greater than−5 mV; or greater than −1 mV; or greater than 1 mV; or greater than 2mV; or greater than 3 mV; or greater than 5 mV; or greater than 10 mV;or greater than 15 mV; or greater than 20 mV; or greater than 25 mV; orgreater than 30 mV; or greater than 35 mV; or greater than 40 mV; orgreater than 45 mV; or greater than 50 mV; or less than 45 mV; or lessthan 40 mV; or less than 35 mV; or less than 30 mV; or less than 25 mV;or less than 20 mV; or less than 15 mV; or less than 10 mV; or less than5 mV; or less than 1 mV; or less than −1 mV; or less than −5 mV; or lessthan −10 mV; or less than −20 mV; or less than −25 mV; or between +50 mVto −25 mV; or between +45 mV to −25 mV; or between +40 mV to −25 mV; orbetween +35 mV to −25 mV; or between +30 mV to −25 mV; or between +25 mVto −25 mV; or between +20 mV to −25 mV; or between +15 mV to −25 mV; orbetween +10 mV to −25 mV; or between +5 mV to −25 mV; or between +1 mVto −25 mV; or between −1 mV to −25 mV; or between −5 mV to −25 mV; orbetween −10 mV to −25 mV; or between −15 mV to −25 mV; or between −20 mVto −25 mV; or between +20 mV to −20 mV; or between +15 mV to −20 mV; orbetween +10 mV to −20 mV; or between +5 mV to −20 mV; or between +1 mVto −20 mV; or between −1 mV to −20 mV; or between −5 mV to −20 mV; orbetween −10 mV to −20 mV; or between −15 mV to −20 mV; or between +25 mVto −10 mV; or between +20 mV to −10 mV; or between +15 mV to −10 mV; orbetween +10 mV to −10 mV; or between +5 mV to −10 mV; or between +1 mVto −10 mV; or between −1 mV to −10 mV; or between −5 mV to −10 mV; orbetween −15 mV to −10 mV; or between −25 mV to −10 mV; or between +25 mVto −5 mV; or between +20 mV to −5 mV; or between +15 mV to −5 mV; orbetween +10 mV to −5 mV; or between +5 mV to −5 mV; or between +1 mV to−5 mV; or between −1 mV to −5 mV; or between −10 mV to −5 mV; or between−15 mV to −5 mV; or between −20 mV to −5 mV; or between −25 mV to −5 mV;or between +25 mV to −1 mV; or between +20 mV to −1 mV; or between +15mV to −1 mV; or between +10 mV to −1 mV; or between +5 mV to −1 mV; orbetween +1 mV to −1 mV; or between −5 mV to −1 mV; or between −10 mV to−1 mV; or between −15 mV to −1 mV; or between −20 mV to −1 mV; orbetween −25 mV to −1 mV; or between 25 mV to 5 mV; or between 20 mV to 5mV; or between 15 mV to 5 mV; or between 10 mV to 5 mV; or between 1 mVto 5 mV; or between −1 mV to +5 mV; or between −5 mV to +5 mV; orbetween −10 mV to +5 mV; or between −15 mV to +5 mV; or between −20 mVto +5 mV; or between −25 mV to +5 mV; or between 25 mV to 10 mV; orbetween 20 mV to 10 mV; or between 15 mV to 10 mV; or between 5 mV to 10mV; or between 1 mV to 10 mV; or between −1 mV to +10 mV; or between −5mV to +10 mV; or between −10 mV to +10 mV; or between −15 mV to +10 mV;or between −20 mV to +10 mV; or between −25 mV to +10 mV; or between 25mV to 20 mV; or between 15 mV to 20 mV; or between 10 mV to 20 mV; orbetween 5 mV to 20 mV; or between 1 mV to 20 mV; or between −1 mV to +20mV; or between −5 mV to +20 mV; or between −10 mV to +20 mV; or between−15 mV to +20 mV; or between −20 mV to +20 mV; or between −25 mV to +20mV; or between 20 mV to 25 mV; or between 15 mV to 25 mV; or between 10mV to 25 mV; or between 5 mV to 25 mV; or between 1 mV to 25 mV; orbetween −1 mV to +25 mV; or between −5 mV to +25 mV; or between −10 mVto +25 mV; or between −15 mV to +25 mV; or between −20 mV to +25 mV. Forexample, the foregoing aspects and the foregoing embodiments, thecomposition includes a zeta potential of between 10 mV to 45 mV; orbetween 15 mV to 45 mV; or between 20 mV to 45 mV; or between 25 mV to45 mV; or between 30 mV to 45 mV; or between 35 mV to 45 mV; or between40 mV to 45 mV. In some embodiments, the composition of the inventionincludes a mix of particles with different zeta potential. For example,two or more, or three or more particles, or 3-20 particles in thecomposition may have different zeta potentials.

In some embodiments, a ratio of calcium to carbonate in the compositionmay affect the zeta potential of the composition. Without being limitedby any theory, it is proposed that the higher ratio of calcium with thecarbonate may result in a higher zeta potential or a positive zetapotential, and the lower ratio of the calcium with the carbonate mayresult in a lower zeta potential or a negative zeta potential. In someembodiments, the ratio of calcium or calcium ion with the carbonate orthe carbonate ion in the composition (calcium:carbonate) is greater than1:1; or greater than 1.5:1; or greater than 2:1; or greater than 2.5:1;or greater than 3:1; or greater than 3.5:1; or greater than 4:1; orgreater than 4.5:1; or greater than 5:1; or is in a range of 1:1 to 5:1;or is in a range of 1.5:1 to 5:1; or is in a range of 2:1 to 5:1; or isin a range of 3:1 to 5:1; or is in a range of 4:1 to 5:1; or is in arange of 1:1 to 4:1; or is in a range of 1.5:1 to 4:1; or is in a rangeof 2:1 to 4:1; or is in a range of 3:1 to 4:1; or is in a range of 1:1to 3:1; or is in a range of 1.5:1 to 3:1; or is in a range of 2:1 to3:1; or is in a range of 1:1 to 2:1; or is in a range of 1.5:1 to 2:1;or is in a range of 1.5:1 to 1:1; or is in a range of 1.2:1 to 1.8:1; oris 1:1; or is 1.5:1; or is 2:1; or is 2.5:1; or is 3:1; or is 3.5:1; oris 4:1; or is 4.5:1; or is 5:1. In some embodiments, the ratio ofcalcium:carbonate in the composition is 1.5:1, or 1:1, or 2:1.

In some embodiments, the ratio of carbonate or the carbonate ion withthe calcium or calcium ion in the composition (carbonate:calcium) isgreater than 1:1; or greater than 1.5:1; or greater than 2:1; or greaterthan 2.5:1; or greater than 3:1; or greater than 3.5:1; or greater than4:1; or greater than 4.5:1; or greater than 5:1; or is in a range of 1:1to 5:1; or is in a range of 1.5:1 to 5:1; or is in a range of 2:1 to5:1; or is in a range of 3:1 to 5:1; or is in a range of 4:1 to 5:1; oris in a range of 1:1 to 4:1; or is in a range of 1.5:1 to 4:1; or is ina range of 2:1 to 4:1; or is in a range of 3:1 to 4:1; or is in a rangeof 1:1 to 3:1; or is in a range of 1.5:1 to 3:1; or is in a range of 2:1to 3:1; or is in a range of 1:1 to 2:1; or is in a range of 1.5:1 to2:1; or is in a range of 1.5:1 to 1:1; or is 1:1; or is 1.5:1; or is2:1; or is 2.5:1; or is 3:1; or is 3.5:1; or is 4:1, or is 4.5:1; or is5:1. In some embodiments, the ratio of carbonate to calcium(carbonate:calcium) in the composition is 1.5:1, or 1:1, or 2:1.

In some embodiments, the composition of the invention includes a ratioof the carbonate to the hydroxide (carbonate:hydroxide) in a range of100:1; or 10:1 or 1:1.

In some embodiments, the compositions contain polymorphs of carbonatesin combination with bicarbonates, e.g., of divalent cations such ascalcium or magnesium; in some cases the composition containssubstantially all polymorphs of carbonates, or substantially allbicarbonates, or some ratio of polymorphs of carbonate to bicarbonate.The molar ratio of carbonates to bicarbonates may be any suitable ratio,such as carbonate:bicarbonate ratio of 500/1 to 100/1; 100/1 to 1/100,or 50/1 to 1/50, or 25/1 to 1/25, or 10/1 to 1/10, or 2/1 to 1/2, orabout 1/1, or substantially all carbonate or substantially allbicarbonate.

In some embodiments, when the compositions of embodiments of theinvention are derived from a saltwater source, they may include one ormore components that are present in the saltwater source which may helpin identifying the compositions that come from the saltwater source.These identifying components and the amounts thereof are collectivelyreferred to herein as a saltwater source identifier or “markers”. Forexample, if the saltwater source is sea water, identifying componentthat may be present in the composition include, but are not limited to:chloride, sodium, sulfur, potassium, bromide, silicon, strontium and thelike. Any such source-identifying or marker elements are generallypresent in small amounts, e.g., in amounts of 20,000 ppm or less, suchas amounts of 2000 ppm or less. In certain embodiments, the markercompounds are strontium or magnesium. The saltwater source identifier ofthe compositions may vary depending on the particular saltwater sourceemployed to produce the saltwater-derived composition. In someembodiments, the composition is characterized by having a water sourceidentifying carbonate to hydroxide compound ratio, where in certainembodiments the carbonate:hydroxide ratio ranges from 100 to 1, such as10 to 1 and including 1 to 1.

In some embodiments, the compositions provided herein further includenitrogen oxide, sulfur oxide, mercury, metal, derivative of any ofnitrogen oxide, sulfur oxide, mercury, and/or metal, or combinationthereof. The derivatives of nitrogen oxide and sulfur oxide include, butnot limited to, nitrates, nitrites, sulfates, and sulfites, etc. Themercury and/or the metal may be present in their derivatized form, suchas, oxides and/or hydroxides, or the mercury and/or the metal may beencapsulated or present in the composition of the invention inun-derivatized form. In some embodiments, the compositions providedherein further includes one or more additional components including, butare not limited to, blast furnace slag, fly ash, diatomaceous earth, andother natural or artificial pozzolans, silica fumes, limestone, gypsum,hydrated lime, air entrainers, retarders, waterproofers and coloringagents. These components may be added to modify the properties of thecement, e.g., to provide desired strength attainment, to provide desiredsetting times, etc. The amount of such components present in a givencomposition of the invention may vary, and in certain embodiments theamounts of these components range from 1 to 50% w/w, or 10% w/w to 50%w/w, such as 2 to 10% w/w.

In some embodiments, silica minerals may co-occur with the vateritecompositions of the invention. These compounds may be amorphous innature or crystalline. In certain embodiments, the silica may be in theform of opal-A, amorphous silica, typically found in chert rocks.Calcium magnesium carbonate silicate amorphous compounds may form,within crystalline regions of the polymorphs listed above.Non-carbonate, silicate minerals may also form. Sepiolite is a claymineral, a complex magnesium silicate, a typical formula for which isMg₄Si₆O₁₅(OH)₂.6H₂O. It can be present in fibrous, fine-particulate, andsolid forms. Silcate carbonate minerals may also form. Carletonite,KNa₄Ca₄(CO₃)4Si₈O₁₈(F, OH).H₂O, Hydrated potassium sodium calciumcarbonate silicate, can form under these conditions. Like any member ofthe phyllosilicates subclass, carletonite's structure is layered withalternating silicate sheets and the potassium, sodium and calciumlayers. Unlike other phyllosilicates, carletonite's silicate sheets arecomposed of interconnected four and eight-member rings. The sheets canbe thought of as being like chicken wire with alternating octagon andsquare shaped holes. Both octagons and squares have a four fold symmetryand this is what gives carletonite its tetragonal symmetry; 4/m 2/m 2/m.Only carletonite and other members of the apophyllite group have thisunique interconnected four and eight-member ring structure.

In some embodiments, the compositions provided herein further includegeopolymers. As used herein, “geopolymers” are conventionally known inthe art and include chains or networks of mineral molecules that includealumina silica chains, such as, —Si—O—Si—O— siloxo, poly(siloxo);—Si—O—Al—O— sialate, poly(sialate); —Si—O—Al—O—Si—O— sialate-siloxo,poly(sialate-siloxo); —Si—O—Al—O—Si—O—Si—O— sialate-disiloxo,poly(sialate-disiloxo); —P—O—P—O— phosphate, poly(phosphate);—P—O—Si—O—P—O— phospho-siloxo, poly(phospho-siloxo); —P—O—Si—O—Al—O—P—O—phospho-sialate, poly(phospho-sialate); and —(R)—Si—O—Si—O—(R)organo-siloxo, poly-silicone. Geopolymers include, but are not limitedto, water-glass based geopolymer, kaolinite/hydrosodalite-basedgeopolymer, metakaolin MK-750-based geopolymer, calcium basedgeopolymer, rock-based geopolymer, silica-based geopolymer, fly-ashbased geopolymer, phosphate based geopolymer, and organic mineralgeopolymer. In some embodiments, the amount of geopolymer added to thecomposition of the invention is 1-50% by wt or 1-25% by wt or 1-10% bywt. The geopolymer can be blended into the composition of the inventionwhich can then be used as a hydraulic cement or SCM. The addition ofgeopolymer to the composition of the invention may decrease the settingtime and/or increase the compressive strength of cement when thecomposition in combination with water sets and hardens into the cement.

In some embodiments, the compositions provided herein further includePortland cement clinker, aggregate, or combination thereof. In someembodiments, the SCM compositions provided herein further includePortland cement clinker, aggregate, supplementary cementitious material(SCM) (such as conventional SCM), or combination thereof. In someembodiments, the SCM is slag, fly ash, silica fume, or calcined clay.

As is known in the art, Portland cements are powder compositionsproduced by grinding Portland cement clinker (more than 90%), a limitedamount of calcium sulfate which controls the set time, and up to 5%minor constituents (as allowed by various standards). As defined by theEuropean Standard EN197.1, “Portland cement clinker is a hydraulicmaterial which shall consist of at least two-thirds by mass of calciumsilicates (3CaO.SiO₂ and 2CaO.SiO₂), the remainder consisting ofaluminium- and iron-containing clinker phases and other compounds. Theratio of CaO:SiO₂ shall not be less than 2.0. The magnesium content(MgO) shall not exceed 5.0% by mass.” In certain embodiments, thePortland cement constituent of the present invention is any Portlandcement that satisfies the ASTM Standards and Specifications of C150(Types I-VIII) of the American Society for Testing of Materials (ASTMC50-Standard Specification for Portland Cement). ASTM C150 covers eighttypes of Portland cement, each possessing different properties, and usedspecifically for those properties.

In some embodiments, the composition of the invention may furtherinclude Ordinary Portland Cement (OPC) or Portland cement clinker. Theamount of Portland cement component may vary and range from 10 to 95%w/w; or 10 to 90% w/w; or 10 to 80% w/w; or 10 to 70% w/w; or 10 to 60%w/w; or 10 to 50% w/w; or 10 to 40% w/w; or 10 to 30% w/w; or 10 to 20%w/w; or 20 to 90% w/w; or 20 to 80% w/w; or 20 to 70% w/w; or 20 to 60%w/w; or 20 to 50% w/w; or 20 to 40% w/w; or 20 to 30% w/w; or 30 to 90%w/w; or 30 to 80% w/w; or 30 to 70% w/w; or 30 to 60% w/w; or 30 to 50%w/w; or 30 to 40% w/w; or 40 to 90% w/w; or 40 to 80% w/w; or 40 to 70%w/w; or 40 to 60% w/w; or 40 to 50% w/w; or 50 to 90% w/w; or 50 to 80%w/w; or 50 to 70% w/w; or 50 to 60% w/w; or 60 to 90% w/w; or 60 to 80%w/w; or 60 to 70% w/w; or 70 to 90% w/w; or 70 to 80% w/w. For example,the composition may include a blend of 75% OPC and 25% composition ofthe invention; or 80% OPC and 20% composition of the invention; or 85%OPC and 15% composition of the invention; or 90% OPC and 10% compositionof the invention; or 95% OPC and 5% composition of the invention. Insome embodiments, such composition of the invention is an SCM.

In certain embodiments, the composition may further include anaggregate. Aggregate may be included in the composition to provide formortars which include fine aggregate and concretes which also includecoarse aggregate. The fine aggregates are materials that almost entirelypass through a Number 4 sieve (ASTM C 125 and ASTM C 33), such as silicasand. The coarse aggregate are materials that are predominantly retainedon a Number 4 sieve (ASTM C 125 and ASTM C 33), such as silica, quartz,crushed round marble, glass spheres, granite, limestone, calcite,feldspar, alluvial sands, sands or any other durable aggregate, andmixtures thereof. As such, the term “aggregate” is used broadly to referto a number of different types of both coarse and fine particulatematerial, including, but are not limited to, sand, gravel, crushedstone, slag, and recycled concrete. The amount and nature of theaggregate may vary widely. In some embodiments, the amount of aggregatemay range from 25 to 80%, such as 40 to 70% and including 50 to 70% w/wof the total composition made up of both the composition and theaggregate.

In some embodiments, the compositions further include a pH regulatingagent which may influence the pH of the fluid component of the settablecomposition produced from the composition or composition mixed withaggregates (to form concrete), upon combination of the composition withwater. Such pH regulating agents may provide for an alkaline environmentupon combination with water, e.g., where the pH of the hydrated cementis 12 or higher, such as 13 or higher, and including 13.5 or higher. Incertain embodiments, the pH regulating (i.e., modulating) agent is anoxide or hydroxide, e.g., calcium oxide, calcium hydroxide, magnesiumoxide or magnesium hydroxide. When present, such agents may be presentin amounts ranging from 1 to 10% w/w, such as 2 to 5% w/w.

In some embodiments, there is provided a settable composition preparedfrom the above recited compositions of the invention. Such settablecompositions include, but are not limited to, cement, concrete, andmortar. Settable compositions may be produced by combining thecomposition of the invention with water or by combining the compositionof the invention with an aggregate and water. The aggregate can be afine aggregate to prepare mortar, such as sand, or a combination of fineand coarse aggregate or coarse aggregate alone for concrete. Thecomposition, the aggregate, and the water may all be mixed at the sametime or the composition may be pre-combined with the aggregate and thepre-combined mixture is then mixed with water. The coarse aggregatematerial for concrete mixes, using the compositions of the invention,may have a minimum size of about ⅜ inch and can vary in size from thatminimum to up to one inch or larger, including gradations between theselimits. Crushed limestone and other rocks, gravel, and the like are someexamples of the coarse aggregates. Finely divided aggregate is smallerthan ⅜ inch in size and may be graduated in much finer sizes down to200-sieve size or so. Ground limestone and other rocks, sand, and thelike are some examples of the fine aggregates. Fine aggregates may bepresent in both mortars and concretes of the invention. The weight ratioof the composition to the aggregate may vary, and in certain embodimentsranges from 1:10 to 4:10, such as 2:10 to 5:10 and including from55:1000 to 70:100.

The aqueous medium, such as, water, with which the dry components arecombined to produce the settable composition, may vary from pure waterto water that includes one or more solutes, additives, co-solvents,etc., as desired. The ratio of the aqueous medium:dry components oraqueous medium:composition of the invention is 0.1-10; or 0.1-8; or0.1-6; or 0.1-4; or 0.1-2; or 0.1-1; or 0.2-10; or 0.2-8; or 0.2-6; or0.2-4; or 0.2-2; or 0.2-1; or 0.3-10; or 0.3-8; or 0.3-6; or 0.3-4; or0.3-2; or 0.3-1; or 0.4-10; or 0.4-8; or 0.4-6; or 0.4-4; or 0.4-2; or0.4-1; or 0.5-10; or 0.5-8; or 0.5-6; or 0.5-4; or 0.5-2; or 0.5-1; or0.6-10; or 0.6-8; or 0.6-6; or 0.6-4; or 0.6-2; or 0.6-1; or 0.8-10; or0.8-8; or 0.8-6; or 0.8-4; or 0.8-2; or 0.8-1; or 1-10; or 1-8; or 1-6;or 1-4; or 1-2; or 0.1; or 0.5; or 1; or 2. In some embodiments, theratio is a weight ratio.

XRD Pattern of the Crystals of the Compositions

In some embodiments, the invention provides a composition that includesa calcium carbonate composition component in which the calcium carbonatecomponent after being in air at 40° C. for at least 8 hours exhibits anx-ray diffraction pattern (XRD) with the peak of most intensity locatedat 32.55° to 32.95°2θ. In some embodiments, the invention provides acomposition that includes a calcium carbonate composition component inwhich the calcium carbonate component after being in air at 40° C. forat least 8 hours exhibits an x-ray diffraction pattern (XRD) with thepeak of most intensity located at 32.55° to 32.95°2θ in which thecalcium carbonate composition component has a relative carbon isotopecomposition (δ¹³C) value less than −5.00‰, or less than −12‰, or lessthan −13‰, or less than −14‰, or less than −15‰, or between −12‰ or−25‰.

In some embodiments, the invention provides a composition including acalcium carbonate composition component wherein the calcium carbonatecomponent after being in air at 40° C. for at least 8 hours exhibits anx-ray diffraction pattern (XRD) with the peak of most intensity locatedat 29.05° to 29.45°2θ. In some embodiments, the invention provides acomposition including a calcium carbonate composition component whereinthe calcium carbonate component after being in air at 40° C. for atleast 8 hours exhibits an x-ray diffraction pattern (XRD) with the peakof most intensity located at 29.05° to 29.45°2θ in which the calciumcarbonate composition component has a relative carbon isotopecomposition (δ¹³C) value less than −5.00‰, or less than −12‰, or lessthan −13‰, or less than −14‰, or less than −15‰, or between −12‰ or−25‰.

In some embodiments, the invention provides a composition including acalcium carbonate composition component wherein the calcium carbonatecomponent after being in air at 40° C. for at least 8 hours exhibits anXRD pattern indicative of the calcium carbonate component including atleast 2 polymorphs of calcium carbonate wherein the peak of mostintensity located at 29.05° to 29.45°2θ, the second most intense peak islocated at 31.50 to 31.905°2θ, and most intense peaks are located at26.85° to 27.50°2θ and 32.55° to 32.95°2θ. In some embodiments, theinvention provides a composition including a calcium carbonatecomposition component wherein the calcium carbonate component afterbeing in air at 40° C. for at least 8 hours exhibits an XRD patternindicative of the calcium carbonate component including at least 2polymorphs of calcium carbonate wherein the peak of most intensitylocated at 29.05° to 29.45°2θ, the second most intense peak is locatedat 31.50 to 31.905°2θ, and the next most intense peaks are located at26.85° to 27.50°2θ and 32.55° to 32.95°2θ in which the calcium carbonatecomposition component has a relative carbon isotope composition (δ¹³C)value less than −5.00‰, or less than −12‰, or less than −15‰, or between−12‰ or −25‰.

In some embodiments, the invention provides a composition including acalcium carbonate composition component wherein the calcium carbonatecomponent after being in air at 40° C. for at least 8 hours exhibits anXRD pattern indicative of the calcium carbonate component including atleast 2 polymorphs of calcium carbonate wherein the peak of mostintensity located at 29.05° to 29.45°2θ, the second most intense peak islocated at 31.50 to 31.905°2θ, and most intense peaks are located at26.85° to 27.50°2θ and 32.55° to 32.95°2θ. In some embodiments, theinvention provides a composition including a calcium carbonatecomposition component wherein the calcium carbonate component afterbeing in air at 40° C. for at least 8 hours exhibits an XRD patternindicative of the calcium carbonate component including at least 2polymorphs of calcium carbonate wherein the peak of most intensitylocated at 29.05° to 29.45°2θ, the second most intense peak is locatedat 31.50 to 31.905°2θ, and the next most intense peaks are located at26.85° to 27.50°2θ and 32.55° to 32.95°2θ in which the calcium carbonatecomposition component has a relative carbon isotope composition (δ¹³C)value less than −5.00‰, or less than −12‰, or less than −15‰, or between−12‰ or −25‰.

In some embodiments, the invention provides a composition including acalcium carbonate composition component having a relative carbon isotopecomposition (δ¹³C) value less than −5.00‰, or less than −12‰, or lessthan −15‰, or between −12‰ or −25‰, wherein the calcium carbonatecomposition comprises at least 2 polymorphs of calcium carbonate.

In some embodiments, the invention provides a composition including acalcium carbonate composition component wherein the calcium carbonatecomponent after being in air at 40° C. for at least 8 hours exhibits anx-ray diffraction pattern (XRD) with the peak of most intensity locatedat 29.05° to 29.45°2θ, the second most intense peak is located at 31.50to 31.90°2θ, and the next most intense peaks are located at 26.85° to27.50°2θ and 32.55° to 32.95°2θ, and further wherein the calciumcarbonate composition component having a relative carbon isotopecomposition (δ¹³C) value less than −5.00‰, or less than −12‰, or lessthan −15‰, or between −12‰ or −25‰.

In some embodiments, the invention provides a composition including acalcium carbonate composition component wherein: the calcium carbonatecomponent comprises at least 2 polymorphs of calcium carbonate; thecalcium carbonate component comprises spherical particulates of calciumcarbonate less than 5 μm in diameter; and the calcium carbonatecomponent has a relative carbon isotope composition (δ¹³C) value lessthan −5.00‰, or less than −12‰, or less than −15‰, or between −12‰ or−25‰. In some embodiments, the invention provides a compositionincluding a calcium carbonate composition component wherein: the calciumcarbonate component comprises at least 2 polymorphs of calciumcarbonate; the calcium carbonate component comprises sphericalparticulates of calcium carbonate less than 5 μm in diameter; and thecalcium carbonate component has a relative carbon isotope composition(δ¹³C) value less than −5.00‰, or less than −12‰, or less than −15‰, orbetween −12‰ or =25‰ in which the spherical particulates are part of anagglomeration of the spherical particulates.

In some embodiments, the invention provides a composition including acalcium carbonate component including at least two polymorphs of calciumcarbonate wherein the calcium carbonate component has a relative carbonisotope composition (δ¹³C) value less than −5.00‰, or less than −12‰, orless than −15‰, or between −12‰ or −25‰ and wherein the calciumcarbonate component after being in air at 40° C. for at least 8 hoursexhibits an x-ray diffraction pattern (XRD) with the peaks of greatestintensity located at 26.85° to 27.50°2θ and 32.55 to 32.95°2θ, furtherwherein, upon mixing with water to form a paste and allowing the pasteto harden over 7 days, the composition exhibits an x-ray diffractionpattern (XRD) with the peak of most intensity located at 29.05° to29.45°2θ.

In some embodiments, the invention provides a composition including acalcium carbonate component including at least two polymorphs of calciumcarbonate wherein the calcium carbonate component has a relative carbonisotope composition (δ¹³C) value less than −5.00‰, or less than −12‰, orless than −15‰, or between −12‰ or −25‰ and wherein the calciumcarbonate component after being in air at 40° C. for at least 8 hoursexhibits an x-ray diffraction pattern (XRD) with the peaks of greatestintensity located at 26.85° to 27.50°2θ and 32.55 to 32.95°2θ, furtherwherein, upon mixing with water to form a paste and allowing the pasteto harden over 7 days, the composition exhibits an x-ray diffractionpattern (XRD) with the peak of most intensity located at 29.05° to29.45°2θ.

In some embodiments, the invention provides a composition includingcalcium carbonate having a relative carbon isotope composition (δ¹³C)value less than −5.00‰, or less than −12‰, or less than −15‰, or between−12‰ or −25‰ wherein after being in air at 40° C. for at least 8 hoursthe composition exhibits an x-ray diffraction pattern (XRD) with thepeaks of greatest intensity located at 26.85° to 27.50°2θ and 32.55 to32.95°2θ and a spherical morphology.

In some embodiments, the invention provides a settable composition thatincludes a calcium carbonate component as previously describedhereinabove.

In some embodiments, the invention provides a method including:contacting a gas including carbon dioxide with an aqueous solution;subjecting the aqueous solution to carbonate precipitation conditions;precipitating a carbonate composition; separating the carbonatecomposition from the aqueous solution; and further processing theaqueous solution and the carbonate composition.

Admixtures

In certain embodiments, the compositions of the invention furtherinclude one or more admixtures. Admixtures may be added to concrete toprovide it with desirable characteristics or to modify properties of theconcrete to make it more readily useable or more suitable for aparticular purpose or for cost reduction. As is known in the art, anadmixture is any material or composition, other than the composition ofthe invention, aggregate and water; that is used as a component of theconcrete or mortar to enhance some characteristic or lower the cost,thereof. The amount of admixture that is employed may vary depending onthe nature of the admixture. In certain embodiments the amounts of thesecomponents range from 1 to 50% w/w, such as 2 to 10% w/w.

The admixtures may provide one or more advantages, such as, (1) achievecertain structural improvements in the resulting cured concrete; (2)improve the quality of concrete through the successive stages of mixing,transporting, placing, and curing during adverse weather or trafficconditions; (3) overcome certain emergencies during concretingoperations; and (4) reduce the cost of concrete construction.

Admixtures of interest include finely divided mineral admixtures, suchas SCM. Finely divided mineral admixtures are materials in powder orpulverized form added to concrete before or during the mixing process toimprove or change some of the plastic or hardened properties ofconcrete. The SCM can be classified according to their chemical orphysical properties as: cementitious materials; pozzolans; pozzolanicand cementitious materials; and nominally inert materials. A pozzolan isa siliceous or aluminosiliceous material that possesses little or nocementitious value but may, in the presence of water and in finelydivided form, chemically react with the calcium hydroxide released bythe hydration of the cement to form materials with cementitiousproperties. Pozzolans can also be used to reduce the rate at which waterunder pressure is transferred through concrete. Diatomaceous earth,opaline cherts, clays, shales, fly ash, silica fume, volcanic tuffs andpumicites are some of the known pozzolans. Certain ground granulatedblast-furnace slags and high calcium fly ashes possess both pozzolanicand cementitious properties. Nominally inert materials can also includefinely divided raw quartz, dolomites, limestone, marble, granite, andothers. Fly ash is defined in ASTM C618.

Plasticizer is another example of the admixture. Plasticizers can beadded to the concrete to provide it with improved workability; ease ofplacement; reduced consolidating effort; and provide uniform flow inreinforced concretes without leaving void space under reinforcing bars.Other examples of admixtures include, but are not limited to,accelerators, retarders, air-entrainers, foaming agents, water reducers,corrosion inhibitors, and pigments. Accelerators may be used to increasethe cure rate (hydration) of the concrete formulation and may be used inapplications where it is desirable for the concrete to harden quicklyand in low temperature applications. Retarders act to slow the rate ofhydration and increase the time available to pour the concrete and toform it into a desired shape. Retarders may be of advantage inapplications where the concrete is being used in hot climates.Air-entrainers are used to distribute tiny air bubbles throughout theconcrete. Air-entrainers may be of advantage for utilization in regionsthat experience cold weather because the tiny entrained air bubbles mayhelp to allow for some contraction and expansion to protect the concretefrom freeze-thaw damage. Pigments can also be added to concrete toprovide it with desired color characteristics for aesthetic purposes.

As such, admixtures of interest include, but are not limited to: setaccelerators, set retarders, air-entraining agents, defoamers,alkali-reactivity reducers, bonding admixtures, dispersants, coloringadmixtures, corrosion inhibitors, damp-proofing admixtures, gas formers,permeability reducers, pumping aids, shrinkage compensation admixtures,fungicidal admixtures, germicidal admixtures, insecticidal admixtures,rheology modifying agents, finely divided mineral admixtures, pozzolans,aggregates, wetting agents, strength enhancing agents, water repellents,and any other concrete or mortar admixture or additive. When using anadmixture, the fresh composition, to which the admixture raw materialsare introduced, is mixed for sufficient time to cause the admixture rawmaterials to be dispersed relatively uniformly throughout the freshconcrete.

Set accelerators may be used to accelerate the setting and earlystrength development of concrete. The set accelerator that can be usedwith the admixture system can be, but is not limited to, a nitrate saltof an alkali metal, alkaline earth metal, or aluminum; a nitrite salt ofan alkali metal, alkaline earth metal, or aluminum; a thiocyanate of analkali metal, alkaline earth metal or aluminum; an alkanolamine; athiosulfate of an alkali metal, alkaline earth metal, or aluminum; ahydroxide of an alkali metal, alkaline earth metal, or aluminum; acarboxylic acid salt of an alkali metal, alkaline earth metal, oraluminum (preferably calcium formate); a polyhydroxylalkylamine; ahalide salt of an alkali metal or alkaline earth metal (e.g., chloride).Examples of set accelerators that may be used in the present dispensingmethod include, but are not limited to, POZZOLITH® NC534, nonchloridetype set accelerator and/or RHEOCRETE® CNI calcium nitrite-basedcorrosion inhibitor, both sold under the above trademarks by BASFAdmixtures Inc. of Cleveland, Ohio.

Also of interest are set retarding admixtures. Set retarding, also knownas delayed-setting or hydration control, admixtures are used to retard,delay, or slow the rate of setting of concrete. They can be added to theconcrete mix upon initial batching or sometime after the hydrationprocess has begun. Set retarders may be used to offset the acceleratingeffect of hot weather on the setting of concrete, or delay the initialset of concrete or grout when difficult conditions of placement occur,or problems of delivery to the job site, or to allow time for specialfinishing processes. Most set retarders may also act as low level waterreducers and can also be used to entrain some air into concrete.Retarders that can be used include, but are not limited to an oxy-boroncompound, corn syrup, lignin, a polyphosphonic acid, a carboxylic acid,a hydroxycarboxylic acid, polycarboxylic acid, hydroxylated carboxylicacid, such as fumaric, itaconic, malonic, borax, gluconic, and tartaricacid, lignosulfonates, ascorbic acid, isoascorbic acid, sulphonicacid-acrylic acid copolymer, and their corresponding salts,polyhydroxysilane, polyacrylamide, carbohydrates and mixtures thereof.Illustrative examples of retarders are set forth in U.S. Pat. Nos.5,427,617 and 5,203,919, which are incorporated herein by reference. Afurther example of a retarder suitable for use in the admixture systemis a hydration control admixture sold under the trademark DELVO® by BASFAdmixtures Inc. of Cleveland, Ohio.

Also of interest as admixtures are air entrainers. The air entrainerincludes any substance that will entrain air in cementitiouscompositions. Some air entrainers can also reduce the surface tension ofa composition at low concentration. Air-entraining admixtures are usedto purposely entrain microscopic air bubbles into concrete.Air-entrainment may improves the durability of concrete exposed tomoisture during cycles of freezing and thawing. In addition, entrainedair may improve concrete's resistance to surface scaling caused bychemical deicers. Air entrainment may also increase the workability offresh concrete while eliminating or reducing segregation and bleeding.Materials used to achieve these desired effects can be selected fromwood resin, natural resin, synthetic resin, sulfonated lignin, petroleumacids, proteinaceous material, fatty acids, resinous acids, alkylbenzenesulfonates, sulfonated hydrocarbons, vinsol resin, anionic surfactants,cationic surfactants, nonionic surfactants, natural rosin, syntheticrosin, an inorganic air entrainer, synthetic detergents, and theircorresponding salts, and mixtures thereof. Air entrainers are added inan amount to yield a desired level of air in a cementitious composition.Examples of air entrainers that can be utilized in the admixture systeminclude, but are not limited to MB AE 90, MB VR and MICRO AIR®, allavailable from BASF Admixtures Inc. of Cleveland, Ohio.

Also of interest as admixtures are defoamers. Defoamers are used todecrease the air content in the cementitious composition. Examples ofdefoamers that can be utilized in the composition include, but are notlimited to mineral oils, vegetable oils, fatty acids, fatty acid esters,hydroxyl functional compounds, amides, phosphoric esters, metal soaps,silicones, polymers containing propylene oxide moieties, hydrocarbons,alkoxylated hydrocarbons, alkoxylated polyalkylene oxides, tributylphosphates, dibutyl phthalates, octyl alcohols, water-insoluble estersof carbonic and boric acid, acetylenic diols, ethylene oxide-propyleneoxide block copolymers and silicones.

Also of interest as admixtures are dispersants. The dispersant includes,but is not limited to, polycarboxylate dispersants, with or withoutpolyether units. The term dispersant is also meant to include thosechemicals that also function as a plasticizer, water reducer such as ahigh range water reducer, fluidizer, antiflocculating agent, orsuperplasticizer for cementitious compositions, such as lignosulfonates,salts of sulfonated naphthalene sulfonate condensates, salts ofsulfonated melamine sulfonate condensates, beta naphthalene sulfonates,sulfonated melamine formaldehyde condensates, naphthalene sulfonateformaldehyde condensate resins for example LOMAR D® dispersant (CognisInc., Cincinnati, Ohio), polyaspartates, or oligomeric dispersants.Polycarboxylate dispersants can be used, by which is meant a dispersanthaving a carbon backbone with pendant side chains, wherein at least aportion of the side chains are attached to the backbone through acarboxyl group or an ether group.

Examples of polycarboxylate dispersants can be found in U.S. Pub. No.2002/0019459, U.S. Pat. No. 6,267,814, U.S. Pat. No. 6,290,770, U.S.Pat. No. 6,310,143, U.S. Pat. No. 6,187,841, U.S. Pat. No. 5,158,996,U.S. Pat. No. 6,008,275, U.S. Pat. No. 6,136,950, U.S. Pat. No.6,284,867, U.S. Pat. No. 5,609,681, U.S. Pat. No. 5,494,516; U.S. Pat.No. 5,674,929, U.S. Pat. No. 5,660,626, U.S. Pat. No. 5,668,195, U.S.Pat. No. 5,661,206, U.S. Pat. No. 5,358,566, U.S. Pat. No. 5,162,402,U.S. Pat. No. 5,798,425, U.S. Pat. No. 5,612,396, U.S. Pat. No.6,063,184, U.S. Pat. No. 5,912,284, U.S. Pat. No. 5,840,114, U.S. Pat.No. 5,753,744, U.S. Pat. No. 5,728,207, U.S. Pat. No. 5,725,657, U.S.Pat. No. 5,703,174, U.S. Pat. No. 5,665,158, U.S. Pat. No. 5,643,978,U.S. Pat. No. 5,633,298, U.S. Pat. No. 5,583,183, and U.S. Pat. No.5,393,343, which are all incorporated herein by reference as if fullywritten out below. The polycarboxylate dispersants of interest include,but are not limited to, dispersants or water reducers sold under thetrademarks GLENIUM® 3030NS, GLENIUM® 3200 HES, GLENIUM 3000NS® (BASFAdmixtures Inc., Cleveland, Ohio), ADVA® (W. R. Grace Inc., Cambridge,Mass.), VISCOCRETE® (Sika, Zurich, Switzerland), and SUPERFLUX® (AximConcrete Technologies Inc., Middlebranch, Ohio).

Also of interest as admixtures are alkali reactivity reducers. Alkalireactivity reducers can reduce the alkali-aggregate reaction and limitthe disruptive expansion forces that this reaction can produce inhardened concrete. The alkali-reactivity reducers include pozzolans (flyash, silica fume), blast-furnace slag, salts of lithium and barium, andother air-entraining agents. Natural and synthetic admixtures are usedto color concrete for aesthetic and safety reasons. These coloringadmixtures are usually composed of pigments and include carbon black,iron oxide, phthalocyanine, umber, chromium oxide, titanium oxide,cobalt blue, and organic coloring agents.

Also of interest as admixtures are corrosion inhibitors. Corrosioninhibitors in concrete may serve to protect embedded reinforcing steelfrom corrosion due to its highly alkaline nature. The high alkalinenature of the concrete may cause a passive and non-corroding protectiveoxide film to form on steel. However, carbonation or the presence ofchloride ions from deicers or seawater can destroy or penetrate the filmand may result in corrosion. Corrosion-inhibiting admixtures maychemically arrest this corrosion reaction. The materials commonly usedto inhibit corrosion are calcium nitrite, sodium nitrite, sodiumbenzoate, certain phosphates or fluorosilicates, fluoroaluminites,amines and related chemicals.

Also of interest are damp-proofing admixtures. Dampproofing admixturesreduce the permeability of concrete that have low cement contents, highwater-cement ratios, or a deficiency of fines in the aggregate. Theseadmixtures retard moisture penetration into dry concrete and includecertain soaps, stearates, and petroleum products. Also of interest aregas former admixtures. Gas formers, or gas-forming agents, are sometimesadded to concrete and grout in very small quantities to cause a slightexpansion prior to hardening. The amount of expansion is dependent uponthe amount of gas-forming material used and the temperature of the freshmixture. Aluminum powder, resin soap and vegetable or animal glue,saponin or hydrolyzed protein can be used as gas formers.

Also of interest are permeability reducers. Permeability reducers may beused to reduce the rate at which water under pressure is transmittedthrough concrete. Silica fume, fly ash, ground slag, natural pozzolans,water reducers, and latex may be employed to decrease the permeabilityof the concrete.

Also of interest are rheology modifying agent admixtures. Rheologymodifying agents may be used to increase the viscosity of cementitiouscompositions. Suitable examples of rheology modifier include firmedsilica, colloidal silica, hydroxyethyl cellulose, hydroxypropylcellulose, fly ash (as defined in ASTM C618), mineral oils (such aslight naphthenic), hectorite clay, polyoxyalkylenes, polysaccharides,natural gums, or mixtures thereof.

Also of interest are shrinkage compensation admixtures. The shrinkagecompensation agent which can be used in the cementitious composition caninclude, but is not limited to, RO(AO)₁₋₁₀H, wherein R is a C₁₋₅ alkylor C₅₋₆ cycloalkyl radical and A is a C₂₋₃ alkylene radical, alkalimetal sulfate, alkaline earth metal sulfates, alkaline earth oxides,preferably sodium sulfate and calcium oxide. TETRAGUARD® is an exampleof a shrinkage reducing agent and is available from BASF Admixtures Inc.of Cleveland, Ohio.

Bacterial and fungal growth on or in hardened concrete may be partiallycontrolled through the use of fungicidal and germicidal admixtures. Thematerials for these purposes include, but are not limited to,polyhalogenated phenols, dialdrin emulsions, and copper compounds.

Also of interest in some embodiments is workability improvingadmixtures. Entrained air, which acts like a lubricant, can be used as aworkability improving agent. Other workability agents are water reducersand certain finely divided admixtures.

In some embodiments, the compositions of the invention are employed withfibers, e.g., where fiber-reinforced concrete is desirable. Fibers canbe made of zirconia containing materials, steel, carbon, fiberglass, orsynthetic materials, e.g., polypropylene, nylon, polyethylene,polyester, rayon, high-strength aramid, (i.e. Kevlar®), or mixturesthereof.

The components of the compositions of the invention can be combinedusing any suitable protocol. Each material may be mixed at the time ofwork, or part of or all of the materials may be mixed in advance.Alternatively, some of the materials are mixed with water with orwithout admixtures, such as high-range water-reducing admixtures, andthen the remaining materials may be mixed therewith. As a mixingapparatus, any conventional apparatus can be used. For example, Hobartmixer, slant cylinder mixer, Omni Mixer, Henschel mixer, V-type mixer,and Nauta mixer can be employed.

Following the combination of the components to produce a settablecomposition (e.g., concrete), the settable composition will set after agiven period of time. The setting time may vary, and in certainembodiments ranges from 30 minutes to 48 hours, such as 30 minutes to 24hours and including from 1 hour to 4 hours. In certain embodiments, thecement products produced from compositions of the invention areextremely durable, e.g., as determined using the test method describedat ASTM C1157.

Building Material

In one aspect, there is provided a structure or a building materialcomprising the composition of the invention or or the set and hardenedform thereof. In some embodiments, the building material is formed fromthe compositions of the invention. Examples of such structures or thebuilding materials include, but are not limited to, building, driveway,foundation, kitchen slab, furniture, pavement, road, bridges, motorway,overpass, parking structure, brick, block, wall, footing for a gate,fence, or pole, and combination thereof. Since these structures orbuilding materials comprise and/or are produced from the compositions ofthe invention, they may include markers or components that identify themas being obtained from carbon dioxide of fossil fuel origin and/or beingobtained from water having trace amounts of various elements present inthe initial salt water source, as described above. For example, wherethe mineral component of the cement component of the concrete is onethat has been produced from sea water, the set product will contain aseawater marker profile of different elements in identifying amounts,such as magnesium, potassium, sulfur, boron, sodium, and chloride, etc.

In one aspect, there is provided a formed building material comprisingthe composition of the invention or or the set and hardened formthereof. In some embodiments, the formed building material is formedfrom the compositions of the invention. The formed building material maybe a pre-cast building material, such as, a pre-cast concrete product.The formed building materials and the methods of making and using theformed building materials are described in U.S. application Ser. No.12/571,398, filed Sep. 30, 2009, which is incorporated herein byreference in its entirety. The formed building materials of theinvention may vary greatly and include materials shaped (e.g., molded,cast, cut, or otherwise produced) into man-made structures with definedphysical shape, i.e., configuration. Formed building materials aredistinct from amorphous building materials (e.g., powder, paste, slurry,etc.) that do not have a defined and stable shape, but instead conformto the container in which they are held, e.g., a bag or other container.Formed building materials are also distinct from irregularly orimprecisely formed materials (e.g., aggregate, bulk forms for disposal,etc.) in that formed building materials are produced according tospecifications that allow for use of formed building materials in, forexample, buildings. Formed building materials may be prepared inaccordance with traditional manufacturing protocols for such structures,with the exception that the composition of the invention is employed inmaking such materials. In some embodiments, the formed buildingmaterials made from the composition of the invention have a compressivestrength of at least 14 MPa; or between about 14-100 MPa; or betweenabout 14-45 MPa; or the compressive strength of the composition of theinvention after setting, and hardening, as described herein. In someembodiments, the formed building materials made from the composition ofthe invention have a δ¹³C of less than −12%; or less than −13%; or lessthan −14%; or less than −15%; or from −15% to −80%; or the δ¹³C of thecomposition of invention, as described herein.

One example of the formed building materials is masonry units. Masonryunits are formed building materials used in the construction ofload-bearing and non-load-bearing structures that are generallyassembled using mortar, grout, and the like. Exemplary masonry unitsformed from the compositions of the invention include bricks, blocks,and tiles. Bricks and blocks of the invention are polygonal structurespossessing linear dimensions. Bricks are masonry units with dimensions(mm) not exceeding 337.5×225×112.5 (length×width×height). Any unit withdimensions (mm) between 337.5×225×112.5 to 2000×1000×500(length×width×depth) is termed a “block.” Structural units withdimensions (mm) exceeding 2000×1000×500 (length×width×depth) are termed“slabs.” Tiles refer to masonry units that possess the same dimensionsas bricks or blocks, but may vary considerably in shape, i.e., may notbe polygonal (e.g., hacienda-style roof tiles).

One type of masonry unit provided by the invention is a brick, whichrefers to a structural unit of material used in masonry construction,generally laid using mortar. Bricks formed from the compositions of theinvention are masonry units with dimensions (mm) not exceeding337.5×225×112.5 (length×width×height). In some embodiments, the bricksmay have lengths ranging from 175 to 300 mm, such as 200 to 250 mm,including 200 to 230 mm; widths ranging from 75 to 150 mm, such as 100to 120 mm, including 100 to 110 mm; and heights ranging from 50 to 90mm, such as 50 to 80 mm, including 55 to 75 mm. Bricks may vary ingrade, class, color, texture, size, weight and can be solid, cellular,perforated, frogged, or hollow. Bricks formed from the compositions ofthe invention may include, but are not limited to, building brick,facing brick, load bearing brick, engineering brick, thin veneer brick,paving brick, glazed brick, firebox brick, chemical resistant brick,sewer and manhole brick, industrial floor brick, etc. The bricks mayalso vary in frost resistance (i.e., frost resistant, moderately frostresistant or non frost resistant), which relates to the durability ofbricks in conditions where exposure to water may result in differentlevels of freezing and thawing. Frost resistant bricks are durable inconditions of constant exposure to water and freezing and thawing.Moderately frost resistant bricks are durable in conditions of sporadicexposure to water and freezing and thawing. Non-frost resistant bricksare not durable in conditions of exposure to water and freezing andthawing. These bricks are suitable only for internal use and are liableto damage by freezing and thawing except when protected by animpermeable cladding during construction. Bricks formed from thecompositions of the invention may also vary in soluble salt content(i.e., low or normal). Percentage by mass of soluble ions in bricks witha low soluble salt content does not exceed 0.03% magnesium, 0.03%potassium, 0.03% sodium, and 0.5% sulfate. Percentage by mass of solubleions in bricks with a normal salt content does not exceed 0.25% ofmagnesium, potassium, and sodium in total and sulfate content does notexceed 1.6%. The bricks may vary considerably in physical and mechanicalproperties. The compressive strength of bricks formed from thecompositions of the invention may range, in certain instances, from 5 to100 MPa; or 20-100 MPa; or 50-100 MPa; or 80-100 MPa; or 20-80 MPa; or20-40 MPa; or 60-80 MPa.

The flexural strength of bricks formed from the compositions of theinvention may vary, ranging from 0.5 to 10 MPa, including 2 to 7 MPa,such as 2 to 5 MPa. The maximum water absorption of bricks may vary,ranging from 5 to 25%, including 10 to 15%. Bricks formed from thecompositions of the invention may also undergo moisture movement(expansion or contraction) due to the absorption or loss of water to itsenvironment. The dimensional stability (i.e., linear shrinkage orexpansion) due to moisture movement may vary, in certain instancesranging from 0.001 to 0.2%, including 0.05 to 0.1%. In some embodiments,the bricks may be used for paving a road. Bricks used to pave areasexposed to heavy traffic (e.g., pedestrian, vehicular, etc.) may have anabrasion resistance index ranging from 0.1 to 0.5, including 0.2 to 0.4,such as 0.3. In addition, bricks formed from the compositions of theinvention may have a volume abrasion loss ranging from 1.0 to 4.0cm³/cm², including 1.5 to 2.5 cm³/cm², or 2.0 cm³/cm². The compositionof the invention may be molded, extruded, or sculpted into the desiredshape and size to form a brick. The shaped composition is then dried andfurther hardened by hydraulic pressure, autoclave or fired in a kiln attemperatures ranging between 900° to 1200° C., such as 900° to 1100° C.and including 1000° C.

Another type of masonry unit provided by the invention is blocks, (e.g.,concrete, cement, foundation, etc.). Blocks are distinct from bricksbased on their structural dimensions. Specifically, blocks exceed thedimensions (mm) of 337.5×225×112.5 (length×width×height). Blocks formedfrom the compositions of the invention may vary in color, texture, size,and weight and can be solid, cellular, and hollow or employ insulation(e.g., expanded polystyrene foam) in the block void volume. Blocks maybe load-bearing, non-load-bearing or veneer (i.e., decorative) blocks.In some embodiments, the blocks may have lengths ranging from 300 to 500mm, such as 350 to 450 mm, widths ranging from 150 to 250 mm, such as180 to 215 mm and heights ranging from 100 to 250 mm, such as 150 to 200mm. The blocks may also vary in faceshell thickness. In some instances,the blocks may have faceshell thicknesses ranging from 15 to 40 mm,including 20 to 30 mm, such as 25 mm. The blocks may also vary in webthickness. In some embodiments, the blocks may have web thicknessesranging from 15 to 30 mm, including 15 to 25 mm, such as 20 mm. Theblocks formed from the compositions of the invention may varyconsiderably in physical and mechanical properties. The compressivestrength of blocks may vary, in certain instances ranging from 5 to 100MPa, including 15 to 75 MPa, such as 20 to 40 MPa. The flexural strengthof blocks formed from the compositions of the invention may also vary,ranging from 0.5 to 15 MPa, including 2 to 10 MPa, such as 4 to 6 MPa.The maximum water absorption of the blocks may vary, ranging from 7 to20% by weight including 8 to 15%, such as 9 to 11%. Blocks formed fromthe compositions of the invention may also undergo moisture movement(expansion or contraction) due to the absorption or loss of water to itsenvironment. Blocks may be Type I moisture-controlled units or Type IInon-moisture-controlled units. The dimensional stability (i.e., linearshrinkage) of the blocks formed from the compositions of the inventionmay vary depending on their intended use and/or geographical location ofuse, in certain instances ranging from 0.02 to 0.15%, such as 0.03 to0.05%. The composition of the invention may be molded, extruded, orsculpted into the desired shape and size to form a block. The shapedcomposition may be further compacted by roller compaction, hydraulicpressure, vibrational compaction, or resonant shock compaction. In someinstances, the resultant composition may also be foamed usingmechanically or chemically introduced gases prior to being shaped orwhile the composition is setting in order to form a lightweight concreteblock. The composition is further cured in an environment with acontrolled temperature and humidity.

Another type of building material provided by the invention is a tile.Tiles formed from the compositions of the invention refer tonon-load-bearing building materials that are commonly employed on roofsand to pave exterior and interior floors of commercial and residentialstructures. Some examples where tiles may be employed include, but arenot limited to, the roofs of commercial and residential buildings,decorative patios, bathrooms, saunas, kitchens, building foyer,driveways, pool decks, porches, walkways, sidewalks, and the like. Tilesmay take on many forms depending on their intended use and/or intendedgeographical location of use, varying in shape, size, weight, and may besolid, webbed, cellular or hollow. Tiles formed from the compositions ofthe invention may vary in dimension, e.g., lengths ranging from 100 to1000 mm, including 250 to 500 mm, such as 250 to 300 mm; widths rangingfrom 50 to 1000 mm, including 100 to 250 mm, such as 125 to 175 mm; andthickness ranging from 10 to 30 mm, including 15 to 25 mm, such as 15 to20 mm. The compressive strengths of tiles formed from the compositionsof the invention may also vary, in certain instances ranging from 5 to75 MPa, including 15 to 40 MPa, such as 25 MPa. The flexural strength oftiles formed from the compositions of the invention may vary, rangingfrom 0.5 to 7.5 MPa, including 2 to 5 MPa, such as 2.5 MPa. The maximumwater absorption of tiles may also vary, in certain instances rangingfrom 5 to 15%, including 7 to 12%. Tiles of the invention may alsoundergo moisture movement (expansion or contraction) due to theabsorption or loss of water to its environment. The dimensionalstability (i.e., linear shrinkage or expansion) due to moisture movementmay vary, in certain instances ranging from 0.001 to 0.25%, including0.025 to 0.075%, such as 0.05%. Tiles used to pave areas exposed toheavy traffic (e.g., pedestrian, vehicular, etc.) may have an abrasionresistance index that may vary considerably, ranging from 0.1 to 0.5,including 0.25. In addition, tiles may have a volume abrasion lossranging from 1.0 to 4.0 cm³/cm², including 1.5 to 3.0 cm³/cm², such as,2.7 cm³/cm². Tiles may be polygonal, circular or take on any otherdesired shape.

As such, the composition of the invention may be molded or cast into thedesired tile shape and size. The shaped composition may be furthercompacted by roller compaction, hydraulic pressure, vibrationalcompaction, or resonant shock compaction. The resultant composition mayalso be poured out into sheets or a roller may be used to form sheets ofa desired thickness. The sheets are then cut to the desired dimensionsof the tiles. In some instances, the resultant composition may also befoamed using mechanically or chemically introduced gases prior to beingshaped or while the composition is setting in order to form alightweight tile. The shaped composition is then allowed to set andfurther cured in an environment with a controlled temperature andhumidity. Tiles may be further polished, colored, textured, shotblasted, inlaid with decorative components and the like.

Construction panels are formed building materials employed in a broadsense to refer to any non-load-bearing structural element that arecharacterized such that their length and width are substantially greaterthan their thickness. Exemplary construction panels formed from thecompositions of the invention include cement boards, fiber-cementsidings, and drywall. Construction panels are polygonal structures withdimensions that vary greatly depending on their intended use. Thedimensions of construction panels may range from 50 to 500 cm in length,including 100 to 300 cm, such as 250 cm; width ranging from 25 to 200cm, including 75 to 150 cm, such as 100 cm; thickness ranging from 5 to25 mm, including 7 to 20 mm, including 10 to 15 mm. Cement boardscomprise construction panels conventionally prepared as a combination ofcement and fiberglass and possess additional fiberglass reinforcement atboth faces of the board. Fiber-cement sidings comprise constructionpanels conventionally prepared as a combination of cement, aggregate,interwoven cellulose, and/or polymeric fibers and possess a texture andflexibility that resembles wood. Drywall comprises construction panelsconventionally prepared from gypsum plaster (i.e., semi-hydrous form ofcalcium sulfate), fibers (glass or paper) and is sandwiched between twosheets of outer material, e.g., paper or fiberglass mats.

One type of construction panel formed from the compositions of theinvention is cement board. They are formed building materials where insome embodiments, are used as backer boards for ceramics that may beemployed behind bathroom tiles, kitchen counters, backsplashes, etc. andmay have lengths ranging from 100 to 200 cm, such as 125 to 175 cm,e.g., 150 to 160 cm; a breadth ranging from 75 to 100 cm, such as 80 to100 cm, e.g., 90 to 95 cm, and a thickness ranging from 5 to 25 mm,e.g., 5 to 15 mm, including 5 to 10 mm. Cement boards of the inventionmay vary in physical and mechanical properties. In some embodiments, theflexural strength may vary, ranging between 1 to 7.5 MPa, including 2 to6 MPa, such as 5 MPa. The compressive strengths may also vary, rangingfrom 5 to 50 MPa, including 10 to 30 MPa, such as 15 to 20 MPa. In someembodiments of the invention, cement boards may be employed inenvironments having extensive exposure to moisture (e.g., commercialsaunas). The maximum water absorption of the cement boards of theinvention may vary, ranging from 5 to 15% by weight, including 8 to 10%,such as 9%. Cement boards formed from the compositions of the inventionmay also undergo moisture movement (expansion or contraction) due to theabsorption or loss of water to its environment. The dimensionalstability (i.e., linear shrinkage or expansion) due to moisture movementmay vary, in certain instances ranging from 0.035 to 0.1%, including0.04 to 0.08%, such as 0.05 to 0.06%. The composition of the inventionmay be used to produce the desired shape and size to form a cementboard. In addition, a variety of further components may be added to thecement boards which include, but are not limited to, plasticizers,foaming agents, accelerators, retarders and air entrainment additives.The composition is then poured out into sheet molds or a roller may beused to form sheets of a desired thickness. The shaped composition maybe further compacted by roller compaction, hydraulic pressure,vibrational compaction, or resonant shock compaction. The sheets arethen cut to the desired dimensions of the cement boards. In someinstances, the resultant composition may also be foamed usingmechanically or chemically introduced gases prior to being shaped orwhile the composition is setting in order to form a lightweight cementboard. The shaped composition is then allowed to set and further curedin an environment with a controlled temperature and humidity. The cementboards formed from the compositions of the invention then may be coveredin a fiberglass mat on both faces of the board. Where desired, thecement boards formed from the compositions of the invention may also beprepared using chemical admixtures such that they possess increasedfire, water, and frost resistance as well as resistance to damage bybio-degradation and corrosion. The cement board may also be combinedwith components such as dispersed glass fibers, which may impartimproved durability, increased flexural strength, and a smoothersurface.

Another type of construction panel provided by the invention isfiber-cement siding. Fiber-cement sidings formed from the compositionsof the invention are formed building materials used to cover theexterior or roofs of buildings and include, but are not limited to,building sheets, roof panels, ceiling panels, eternits, and the like.They may also find use as a substitute for timber fascias and bargeboards in high fire areas. Fiber-cement sidings may have dimensions thatvary, ranging from 200 to 400 cm in length, e.g., 250 cm and 50 to 150cm in width, e.g., 100 cm and a thickness ranging from 4 to 20 mm, e.g.,5 to 15 mm, including 10 mm. Fiber-cement sidings formed from thecompositions of the invention may possess physical and mechanicalproperties that vary. In some embodiments, the flexural strength mayrange between 0.5 to 5 MPa, including 1 to 3 MPa, such as 2 MPa. Thecompressive strengths may also vary, in some instances ranging from 2 to25 MPa, including 10 to 15 MPa, such as 10 to 12 MPa. In someembodiments of the invention, fiber-cement sidings may be employed onbuildings that are subject to varying weather conditions, in someembodiments ranging from extremely arid to wet (i.e., low to high levelsof humidity). Accordingly, the maximum water absorption of thefiber-cement sidings of the invention may vary, ranging from 10 to 25%by mass, including 10 to 20%, such as 12 to 15%. The dimensionalstability (i.e., linear shrinkage or expansion) due to moisture movementmay vary, in certain instances ranging from 0.05 to 0.1%, including 0.07to 0.09%. The composition of the invention may be used to produce thedesired shape and size to form a fiber-cement siding. In addition, avariety of further components may be added to the fiber-cement sidingswhich include, but are not limited to, cellulose fibers, plasticizers,foaming agents, accelerators, retarders and air entrainment additives.The composition is then poured into sheet molds or a roller is used toform sheets of a desired thickness. The shaped composition may befurther compacted by roller compaction, hydraulic pressure, vibrationalcompaction, or resonant shock compaction. The sheets are then cut to thedesired dimensions of the fiber-cement sidings. In some instances, theresultant composition may also be foamed using mechanically orchemically introduced gases prior to being shaped or while thecomposition is setting in order to form a lightweight fiber-cementsiding. The shaped composition is then allowed to set and further curedin an environment with a controlled temperature and humidity. Thefiber-cement sidings of the invention may then be covered with apolymeric film, enamel or paint. Where desired, the fiber-cement sidingsformed from the compositions of the invention may also be prepared usingchemical admixtures such that they possess increased fire, water, andfrost resistance as well as resistance to damage by bio-degradation andcorrosion.

Another type of construction panel formed from the compositions of theinvention is drywall. The term drywall refers to the commonlymanufactured building material that is used to finish construction ofinterior walls and ceilings. In certain instances, drywall buildingmaterials are panels that are made of a paper liner wrapped around aninner core. The inner core of drywall of the invention will include atleast some amount of the composition of the invention. The dimensions ofthe drywall building materials of the invention may vary, in certaininstances ranging from 100 to 200 cm, such as 125 to 175 cm, e.g., 150to 160 cm in length; ranging from 75 to 100 cm, such as 80 to 100 cm,e.g., 90 to 95 cm in breadth, and ranging from 5 to 50 mm, e.g., 5 to 30mm, including 10 to 25 mm in thickness. Drywall provided by theinvention may possess physical and mechanical properties that varyconsiderably, and may depend upon the amount of the conventionalconstituents of drywall preparation that are replaced with thecomposition of the invention. The flexural and compressive strengths ofdrywall provided by the invention are generally larger than conventionaldrywall prepared with gypsum plaster, which is known to be a softconstruction material. In some embodiments, the flexural strength mayrange between 0.1 to 3 MPa, including 0.5 to 2 MPa, such as 1.5 MPa. Thecompressive strengths may also vary, in some instances ranging from 1 to20 MPa, including 5 to 15 MPa, such as 8 to 10 MPa. The maximum waterabsorption of drywall of the invention may vary, ranging from 2 to 10%by mass, including 4 to 8%, such as 5%. In certain embodiments, theinner core will be analogous to a conventional drywall core which ismade primarily from gypsum plaster (the semi-hydrous form of calciumsulfate (CaSO₄.½H₂O), with at least a portion of the gypsum componentreplaced with the composition of the invention. In addition, the coremay include a variety of further components, such as, but not limitedto, fibers (e.g., paper and/or fiberglass), plasticizers, foamingagents, accelerators, e.g., potash, retarders, e.g., EDTA or otherchelators, various additives that increase mildew and fire resistance(e.g., fiberglass or vermiculite), and water. The portion of componentsreplaced with the composition of the invention may vary, and in certaininstances is 5% by weight or more, including 10% by weight or more, 25%by weight or more, 50% by weight or more, 75% by weight or more, 90% byweight or more, or even 100% by weight. In producing the drywall, thecore components may be combined and the resultant composition sandwichedbetween two sheets of outer material, e.g., heavy paper or fiberglassmats. When the core sets and is dried in a large drying chamber, thesandwich becomes rigid and strong enough for use as a building material.

Another building material formed from the compositions of the inventionis a conduit. Conduits are tubes or analogous structures configured toconvey a gas or liquid, from one location to another. Conduits of theinvention can include any of a number of different structures used inthe conveyance of a liquid or gas that include, but are not limited to,pipes, culverts, box culverts, drainage channels and portals, inletstructures, intake towers, gate wells, outlet structures, and the like.Conduits of the invention may vary considerably in shape, which isgenerally determined by hydraulic design and installation conditions.Shapes of conduits of the invention may include, but are not limited tocircular, rectangular, oblong, horseshoe, square, etc. Multiple cellconfigurations of conduits are also possible. Conduit design may varydepending on its intended use. As such, conduits formed from thecompositions of the invention may have dimensions that varyconsiderably. Conduits may have outer diameters which range in lengthfrom 5 to 500 cm or longer, such as 10 to 300 cm, e.g., 25 to 250 cm.The wall thicknesses may vary considerably, ranging in certain instancesfrom 0.5 to 25 cm or thicker, such as 1 to 15 cm, e.g., 1 to 10 cm. Incertain embodiments, conduits may be designed in order to support highinternal pressure from water flow within the conduit. In yet otherembodiments, conduits formed from the compositions of the invention maybe designed to support high external loadings (e.g., earth loads,surface surcharge loads, vehicle loads, external hydrostatic pressures,etc.). Accordingly, the compressive strength of the walls of conduits ofthe invention may also vary, depending on the size and intended use ofthe conduit, in some instances ranging, from 5 to 75 MPa, such as 10 to50 MPa, e.g., 15 to 40 MPa. Where desired, the conduits may be employedwith various coatings or liners (e.g., polymeric), and may be configuredfor easy joining with each other to produce long conveyance structuresmade up of multiple conduits of the invention. In producing conduits ofthe invention, the composition after combining with water is poured intoa mold in order to form the desired conduit shape and size. The shapedcomposition may be further compacted by roller compaction, hydraulicpressure, vibrational compaction, or resonant shock compaction. In someinstances, the resultant composition may also be foamed usingmechanically or chemically introduced gases prior to being shaped orwhile the composition is setting in order to form a lightweight conduitstructure. The shaped composition is further allowed to set and is curedin an environment with a controlled temperature and humidity. Inaddition, the conduits of the invention may include a variety of furthercomponents, such as, but not limited to, plasticizers, foaming agents,accelerators, retarders and air entrainment additives. Where desired,the further components may include chemical admixtures such that theconduits of the invention possess increased resistance to damage bybio-degradation, frost, water, fire and corrosion. In some embodiments,the conduits formed from the compositions of the invention may employstructural support components such as, but not limited to, cables, wiresand mesh composed of steel, polymeric materials, ductile iron, aluminumor plastic.

Another building material formed from the compositions of the inventionis basins. The term basin may include any configured container used tohold a liquid, such as water. As such, a basin may include, but is notlimited to structures such as wells, collection boxes, sanitarymanholes, septic tanks, catch basins, grease traps/separators, stormdrain collection reservoirs, etc. Basins may vary in shape, size, andvolume capacity. Basins may be rectangular, circular, spherical, or anyother shape depending on its intended use. In some embodiments, basinsmay possess a greater width than depth, becoming smaller toward thebottom. The dimensions of the basin may vary depending on the intendeduse of the structure (e.g., from holding a few gallons of liquid toseveral hundred or several thousand or more gallons of liquid). The wallthicknesses may vary considerably, ranging in certain instances from 0.5to 25 cm or thicker, such as 1 to 15 cm, e.g., 1 to 10 cm. Accordingly,the compressive strength may also vary considerably, depending on thesize and intended use of the basin, in some instances ranging, from 5 to60 MPa, such as 10 to 50 MPa, e.g., 15 to 40 MPa. In some embodiments,the basin may be designed to support high external loadings (e.g., earthloads, surface surcharge loads, vehicle loads, etc.). In certain otherembodiments, the basins may be employed with various coatings or liners(e.g., polymeric), and may be configured so that they may be combinedwith conveyance elements (e.g., drainage pipe). In other embodiments,basins may be configured so that they may be connected to other basinsso that they may form a connected series of basins. In producing basins,the composition after combining with water may be poured into a mold toform the desired basin shape and size. The shaped composition may befurther compacted by roller compaction, hydraulic pressure, vibrationalcompaction, or resonant shock compaction. The basins may also beprepared by pouring the composition into sheet molds and the basinsfurther assembled by combining the sheets together to form basins withvarying dimensions (e.g., polygonal basins, rhomboidal basins, etc.). Insome instances, the resultant composition may also be foamed usingmechanically or chemically introduced gases prior to being shaped orwhile the composition is setting in order to form a lightweight basinstructure. The shaped composition is further allowed to set and is curedin an environment with a controlled temperature and humidity. Inaddition, the basins formed from the compositions of the invention mayinclude a variety of further components, such as, but not limited to,plasticizers, foaming agents, accelerators, retarders and airentrainment additives. Where desired, the further components may includechemical admixtures such that the basins of the invention possessincreased resistance to damage by bio-degradation, frost, water, fireand corrosion. In some embodiments, the basins of the invention mayemploy structural support components such as, but not limited to,cables, wires and mesh composed of steel, polymeric materials, ductileiron, aluminum or plastic.

Another building material formed from the compositions of the inventionis a beam, which, in a broad sense, refers to a horizontal load-bearingstructure possessing large flexural and compressive strengths. Beams maybe rectangular cross-shaped, C-channel, L-section edge beams, I-beams,spandrel beams, H-beams, possess an inverted T-design, etc. Beams of theinvention may also be horizontal load-bearing units, which include, butare not limited to joists, lintels, archways and cantilevers. Beamsgenerally have a much longer length than their longest cross-sectionaldimension, where the length of the beam may be 5-fold or more, 10-foldor more, 25-fold or more, longer than the longest cross-sectionaldimension. Beams formed from the compositions of the invention may varyin their mechanical and physical properties. For example, unreinforcedconcrete beams may possess flexural capacities that vary, ranging from 2to 25 MPa, including 5 to 15 MPa, such as 7 to 12 MPa and compressivestrengths that range from 10 to 75 MPa, including 20 to 60 MPa, such as40 MPa. Structurally reinforced concrete beams may possess considerablylarger flexural capacities, ranging from 15 to 75 MPa, including as 25to 50 MPa, such as 30 to 40 MPa and compressive strengths that rangefrom 35 to 150 MPa, including 50 to 125 MPa, such as 75 to 100 MPa. Thebeams formed from the compositions of the invention may be internal orexternal, and may be symmetrically loaded or asymmetrically loaded. Insome embodiments, beams may be composite, wherein it acts compositelywith other structural units by the introduction of appropriate interfaceshear mechanisms. In other embodiments, beams may be non-composite,wherein it utilizes the properties of the basic beam alone. In producingbeams of the invention, the composition of the invention after mixingwith water may be poured into a beam mold or cast around a correlatedsteel reinforcing beam structure (e.g., steel rebar). In someembodiments, the steel reinforcement is pretensioned prior to castingthe composition around the steel framework. In other embodiments, beamsof the invention may be cast with a steel reinforcing cage that ismechanically anchored to the concrete beam. The beams of the inventionmay also employ additional structural support components such as, butnot limited to cables, wires and mesh composed of steel, ductile iron,polymeric fibers, aluminum or plastic. The structural support componentsmay be employed parallel, perpendicular, or at some other angle to thecarried load. The molded or casted composition may be further compactedby roller compaction, hydraulic pressure, vibrational compaction, orresonant shock compaction. The composition is further allowed to set andis cured in an environment with a controlled temperature and humidity.In addition, the beams of the invention may include a variety of furthercomponents, such as but not limited to, plasticizers, foaming agents,accelerators, retarders and air entrainment additives. Where desired,the further components may include chemical admixtures such that thebeams of the invention possess increased resistance to damage bybio-degradation, frost, water, fire and corrosion.

Another building material formed from the compositions of the inventionis a column, which, in a broad sense, refers to a vertical load-bearingstructure that carries loads chiefly through axial compression andincludes structural elements such as compression members. Other verticalcompression members of the invention may include, but are not limited topillars, piers, pedestals, or posts. Columns formed from thecompositions of the invention may be rigid, upright supports, composedof relatively few pieces. Columns may also be decorative pillars havinga cylindrical or polygonal, smooth or fluted, tapered or straight shaftwith a capital and usually a base, among other configurations. Thecapital and base of the column may have a similar shape as the column ormay be different. Any combination of shapes for the capital and base ona column are possible. Polygonal columns formed from the compositions ofthe invention possess a width that is not more than four times itsthickness. Columns formed from the compositions of the invention may beconstructed such that they are solid, hollow (e.g., decorative columns),reinforcement filled, or any combination thereof. Columns can be shortcolumns (i.e., columns where strength is governed by constructioncomponents and the geometry of its cross section) or slender columns(i.e., cross-sectional dimensions that are less than 5 times itslength). The dimensions of the column may vary greatly depending on theintended use of the structure, e.g., from being less than a single storyhigh, to several stories high or more, and having a corresponding width.Columns may vary in their mechanical and physical properties.

Properties such as compressive and flexural strengths may vary dependingon the design and intended use of the column. For example, unreinforcedconcrete columns may possess flexural strengths that range from 2 to 20MPa, including 5 to 15 MPa, such as 7 to 12 MPa and compressivestrengths that range from 10 to 100 MPa, including 25 to 75 MPa, such as50 MPa. Structurally reinforced concrete columns of the invention maypossess considerably larger flexural strengths, ranging from 15 to 50MPa, including 20 to 40 MPa, such as 25 to 35 MPa and compressivestrengths that range from 25 to 200 MPa, including 50 to 150 MPa, suchas 75 to 125 MPa. In some embodiments, columns may be composite, whereinit may act compositely with other structural units by the introductionof interfacial shear mechanisms. In other embodiments, columns may benon-composite, wherein it utilizes the properties of the basic columnalone. In producing columns of the invention, the composition aftercombination with water may be poured into a column form or cast around acorrelated steel reinforcing column structure (e.g., steel rebar). Insome embodiments, the steel reinforcement is pre-tensioned prior tocasting the composition around the steel framework. In otherembodiments, columns of the invention may be cast with a steelreinforcing cage that is mechanically anchored to the concrete column.The columns of the invention may also employ additional structuralsupport components such as, but not limited to, cables, wires and meshcomposed of steel, ductile iron, polymeric fibers, aluminum or plastic.The structural support components may be employed parallel,perpendicular, or at some other angle to the carried load. The molded orcasted composition may be further compacted by roller compaction,hydraulic pressure, vibrational compaction, or resonant shockcompaction. The composition is further allowed to set and is cured in anenvironment with a controlled temperature and humidity. In addition, thecolumns of the invention may include a variety of additional components,such as but not limited to, plasticizers, foaming agents, accelerators,retarders and air entrainment additives. Where desired, these additionalcomponents may include chemical admixtures such that the columns of theinvention possess increased resistance to damage by bio-degradation,frost, water, fire and corrosion.

Another building material formed from the compositions of the inventionis a concrete slab. Concrete slabs are those building materials used inthe construction of prefabricated foundations, floors and wall panels.In some instances, a concrete slab may be employed as a floor unit(e.g., hollow plank unit or double tee design). In other instances, aprecast concrete slab may be a shallow precast plank used as afoundation for in-situ concrete formwork. Wall panels are, in a broadsense, vertical load-bearing members of a building that are polygonaland possess a width that is more than four times its thickness. Precastconcrete foundation, floors and wall panels may vary considerably indimension depending on the intended use of the precast concrete slab(e.g., one or two storey building). As such, precast concrete slabs mayhave dimensions which range from 1 to 10 m in length or longer,including 3 to 8 m, such as 5 to 6 m; height that ranges from 1 to 10 mor taller, including 4 to 10 m, such as 4 to 5 m; and a thickness thatmay range from 0.005 to 0.25 m or thicker, including 0.1 to 0.2 m suchas 0.1 to 0.15 m. Formed building materials such as slabs, andstructures made therefrom, may be thicker than corresponding structuresthat lack components of the composition of the invention. In addition,structures made from amorphous building materials formed from thecomposition of the invention may be thicker than correspondingstructures that are not formed from the composition of the invention.

In some embodiments, thickness of formed building materials or relatedstructures is increased by 1.5 fold or more, 2-fold or more, or 5-foldor more. Concrete slabs formed from the compositions of the inventionmay vary in their mechanical and physical properties depending on theirintended use. For example, a prefabricated slab that is employed in afloor unit may possess larger flexural strengths and lesser compressivestrengths than a slab that is employed as a load-bearing wall. Forexample, unreinforced concrete slabs may possess flexural strengths thatvary, ranging from 2 to 25 MPa, including 5 to 15 MPa, such as 7 to 12MPa and compressive strengths that range from 10 to 100 MPa, including25 to 75 MPa, such as 50 MPa. Structurally reinforced concrete slabs ofthe invention may possess considerably larger flexural strengths,ranging from 15 to 50 MPa, including 20 to 40 MPa, such as 25 to 35 MPaand compressive strengths that range from 25 to 200 MPa, including 50 to150 MPa, such as 75 to 125 MPa. In producing concrete slabs, thecomposition after combination with water may be poured into a slab moldor cast around a correlated steel reinforcing structure (e.g., steelrebar). In some embodiments, the steel reinforcement is pretensionedprior to casting the composition around the steel framework. In otherembodiments, slabs of the invention may be cast with a steel reinforcingcage that is mechanically anchored to the concrete slab. In someembodiments, the concrete slabs of the invention may improve itsstructural capacity by casting a second, supportive concrete layer thatis mechanically anchored to the previously precast concrete slab. Theslabs formed from the compositions of the invention may also employadditional structural support components such as, but not limited to,cables, wires and mesh composed of steel, ductile iron, polymericfibers, aluminum or plastic. The structural support components may beemployed parallel, perpendicular, or at some other angle to the carriedload. The molded or casted composition may be further compacted byroller compaction, hydraulic pressure, vibrational compaction, orresonant shock compaction. The composition is further allowed to set andis cured in an environment with a controlled temperature and humidity.In addition, the slabs of the invention may include a variety of furthercomponents, such as but not limited to, plasticizers, foaming agents,accelerators, retarders and air entrainment additives. Where desired,the further components may include chemical admixtures such that theslabs formed from the compositions of the invention possess increasedresistance to damage by bio-degradation, frost, water, fire andcorrosion.

Another building material formed from the compositions of the inventionis an acoustic barrier, which refers to a structure used as a barrierfor the attenuation or absorption of sound. As such, an acoustic barriermay include, but is not limited to, structures such as acousticalpanels, reflective barriers, absorptive barriers, reactive barriers,etc. Acoustic barriers formed from the compositions of the invention maywidely vary in size and shape. Acoustic barriers may be polygonal,circular, or any other shape depending on its intended use. Acousticbarrier may be employed in the attenuation of sound from highways,roadways, bridges, industrial facilities, power plants, loading docks,public transportation stations, military facilities, gun ranges, housingcomplexes, entertainment venues (e.g., stadiums, concert halls) and thelike. Acoustic barriers may also be employed for sound insulation forthe interior of homes, music studios, movie theaters, classrooms, etc.The acoustic barriers formed from the compositions of the invention mayhave dimensions that vary greatly depending on its intended use, rangingfrom 0.5 to 10 m in length or longer, e.g., 5 m and 0.1 to 10 m inheight/width or wider, e.g., 5 m and a thickness ranging from 10 to 100cm, or thicker e.g., 25 to 50 cm, including 40 cm. Where desired, theacoustic barrier may be employed with various coatings or liners (e.g.,polymeric), and may be configured for easy joining with each other orpillars separating additional acoustic barriers to produce long acousticbarrier structures made up of multiple acoustic barriers of theinvention. In some embodiments, acoustic barriers formed from thecompositions of the invention may employ sound absorptive material(e.g., wood shavings, textile fibers, glass wool, rock wool, polymericfoam, vermiculite, etc.) in addition to a structurally reinforcingframework. In some embodiments, acoustic barriers may be used asnoise-reduction barriers in an outdoor environment (e.g., along ahighway, near an airport, etc.) and may be employed with structuralsupport components (e.g., columns, posts, beams, etc.). In producingacoustic barriers of the invention, the composition of the inventionafter combination with water is poured into a mold to form the desiredacoustic barrier shape and size. Also the composition may be poured outinto a sheet mold or a roller may be used to form sheets of a desiredthickness. The shaped composition may be further compacted by rollercompaction, hydraulic pressure, vibrational compaction, or resonantshock compaction. The sheets are then cut to the desired dimensions ofthe acoustic barriers. In some instances, the resultant composition mayalso be foamed using mechanically or chemically introduced gases priorto being shaped or while the composition is setting in order to form alightweight acoustic panel structure. The shaped composition is furtherallowed to set and is cured in an environment with a controlledtemperature and humidity. In addition, the acoustic barriers of theinvention may include a variety of further components, such as but notlimited to, plasticizers, foaming agents, accelerators, retarders andair entrainment additives. Where desired, the further components mayinclude chemical admixtures such that they possess increased resistanceto damage by bio-degradation, frost, water, fire and corrosion. In someembodiments, the acoustic barriers of the invention may employstructural support components such as, but not limited to, cables, wiresand mesh composed of steel, ductile iron, polymeric fibers, aluminum orplastic.

Another building material formed from the compositions of the inventionis an insulation material, which refers to a material used to attenuateor inhibit the conduction of heat. Insulation may also include thosematerials that reduce or inhibit radiant transmission of heat.Insulation material may consist of one or more of the followingconstituents: a cementitious forming material, a dispersing agent, anair entraining agent, inert densifying particulate, a mixture of ionicand non-ionic surfactants, plasticizers, accelerators, lightweightaggregate, organic and inorganic binding agents and glass particles. Incertain embodiments of the invention, an amount of cementitious formingmaterial may be replaced by the above described composition of theinvention. Binding compositions for the insulation material of theinvention include a component selected from the group consisting ofcarbides, Gypsum powder, Blakite, nitrides, calcium carbonate, oxides,titanates, sulfides, zinc selenide, zinc telluride, inorganic siloxanecompound and their mixtures thereof. In certain embodiments of theinvention, an amount of the binding composition may be replaced by theabove described composition of the invention. Where desired, insulationmaterial of the invention may also be prepared using a chemicaladmixture or any other convenient protocol such that they are resistantto damage by termites, insects, bacteria, fungus. Etc. Insulationmaterials of the invention may be prepared using any convenient protocolsuch that they are freeze/thaw, rain and fire resistant. Insulationmaterial of the invention may be prepared in accordance with traditionalmanufacturing protocols for such materials, with the exception that thecomposition of the invention is employed. In producing the insulationmaterials of the invention, an amount of the composition of theinvention may be combined with water and other components of theinsulation material, which may include, but are not limited to adispersing agent, an air entraining agent, inert densifying particulate,a mixture of ionic and non-ionic surfactants, plasticizers,accelerators, lightweight aggregate, organic and inorganic bindingagents and glass particles. The resultant insulation material may thenbe molded into the desired shape (e.g., wall panel) or poured into thevoid space of concrete masonry units, flooring units, roof decks or castaround pipes, conduits and basins.

In some embodiments, the formed building material such as pre-castconcrete products include, but are not limited to, bunker silo; cattlefeed bunk; cattle grid; agricultural fencing; H-bunks; J-bunks;livestock slats; livestock watering troughs; architectural panel walls;cladding (brick); building trim; foundation; floors, including slab ongrade; walls; double wall precast sandwich panel; aqueducts;mechanically stabilized earth panels; box culverts; 3-sided culverts;bridge systems; RR crossings; RR ties; sound walls/barriers; Jerseybarriers; tunnel segments; reinforced concrete box; utillity protectionstructure; hand holes; hollowcore product; light pole base; meter box;panel vault; pull box; telecom structure; transformer pad; transformervault; trench; utility vault; utility pole; controlled environmentvaults; underground vault; mausoleum; grave stone; coffin; haz matstorage container; detention vaults; catch basins; manholes; aerationsystem; distribution box; dosing tank; dry well; grease interceptor;leaching pit; sand-oil/oil-water interceptor; septic tank; water/sewagestorage tank; wetwells; fire cisterns; floating dock; underwaterinfrastructure; decking; railing; sea walls; roofing tiles; pavers;community retaining wall; res. retaining wall; modular block systems;and segmental retaining walls.

Aggregate

In some embodiments the invention provides a synthetic rock or anaggregate comprising the composition of the invention or or the set andhardened form thereof. In some embodiments, the aggregate is made fromthe compositions of the invention. The aggregates and the methods ofmaking and using the aggregates are described in U.S. application Ser.No. 12/475,378, filed May 29, 2009, which is incorporated herein byreference in its entirety. The aggregate may be formed from hydrauliccement or SCM or self-cementing composition of the invention. In someembodiments, aggregates are formed, in whole or in part, fromcompositions of the invention that have been exposed to freshwater andallowed to harden into stable compounds, which may then be furtherprocessed, if necessary, to form particles as appropriate to the type ofaggregate desired. In some embodiments, aggregates are formed fromcompositions of the invention exposed to conditions of temperatureand/or pressure that convert them into stable compounds. The inventionfurther provides structures, such as roadways, buildings, dams, andother manmade structures, containing the synthetic rock or aggregatesmade from the compositions of the invention.

In some embodiments, some or all the embodiments recited above for thecomposition of the invention also apply to the aggregates made from thecompositions of the invention.

The term aggregate is used herein in its art-accepted manner to includea particulate composition that finds use in concretes, mortars and othermaterials, e.g., roadbeds, asphalts, and other structures and issuitable for use in such structures. Aggregates of the invention areparticulate compositions that may in some embodiments be classified asfine or coarse. Fine aggregates according to embodiments of theinvention are particulate compositions that almost entirely pass througha Number 4 sieve (ASTM C 125 and ASTM C 33). Fine aggregate compositionsaccording to embodiments of the invention have an average particle sizeranging from 0.001 inch (in) to 0.25 in, such as 0.05 in to 0.125 in andincluding 0.01 in to 0.08 in. Coarse aggregates of the invention arecompositions that are predominantly retained on a Number 4 sieve (ASTM C125 and ASTM C 33). Coarse aggregate compositions according toembodiments of the invention are compositions that have an averageparticle size ranging from 0.125 in to 6 in, such as 0.187 in to 3.0 inand including 0.25 in to 1.0 in. As used herein, “aggregate” may also insome embodiments encompass larger sizes, such as 3 in to 12 in or even 3in to 24 in, or larger, such as 12 in to 48 in, or larger than 48 in,e.g., such as sizes used in riprap and the like. In some embodiments,such as producing wave-resistant structures for the ocean, the sizes maybe even larger, such as over 48 in, e.g., over 60 in, or over 72 in.

Significant properties of the compositions may include one or more ofhardness, abrasion resistance, density, porosity, chemical composition,mineral composition, isotopic composition, size, shape, acid resistance,alkaline resistance, leachable chloride content, retention of CO₂,reactivity (or lack thereof).

Aggregates formed from the compositions of the invention have a densitythat may vary so long as the aggregate provides the desired propertiesfor the use for which it will be employed, e.g., for the buildingmaterial in which it is employed. In certain instances, the density ofthe aggregate particles ranges from 1.1 to 5 gm/cc, such as 1.3 gm/cc to3.15 gm/cc, and including 1.8 gm/cc to 2.7 gm/cc. Other particledensities in embodiments of the invention, e.g., for lightweightaggregates, may range from 1.1 to 2.2 gm/cc, e.g, 1.2 to 2.0 g/cc or 1.4to 1.8 g/cc. In some embodiments the invention provides aggregates thatrange in bulk density (unit weight) from 50 lb/ft³ to 200 lb/ft³, or 75lb/ft³ to 175 lb/ft³, or 50 lb/ft³ to 100 lb/ft³, or 75 lb/ft³ to 125lb/ft³, or 90 lb/ft³ to 115 lb/ft³, or 100 lb/ft³ to 200 lb/ft³, or 125lb/ft³ to 175 lb/ft³, or 140 lb/ft³ to 160 lb/ft³, or 50 lb/ft³ to 200lb/ft³. Some embodiments of the invention provide lightweight aggregate,e.g., aggregate that has a bulk density (unit weight) of 75 lb/ft³ to125 lb/ft³. Some embodiments of the invention provide lightweightaggregate, e.g., aggregate that has a bulk density (unit weight) of 90lb/ft³ to 115 lb/ft³.

The hardness of the aggregate particles making up the aggregate may alsovary, and in certain instances the hardness, expressed on the Mohsscale, ranges from 1-9; or 1-7; or 1-6; or 1-5; or 1-4; or 2-9; or 2-8;or 2-7; or 2-6; or 2-5; or 2-4; or 2-3; or 3-9; or 3-8; or 3-7; or 3-6;or 3-5; or 3-4; or 4-9; or 4-8; or 4-7; or 4-6; or 4-5; or 5-9; or 5-8;or 5-7; or 5-6; or 6-9; or 6-8; or 6-7; or 7-9; or 7-8; or 8-9. Otherhardness scales may also be used to characterize the aggregate, such asthe Rockwell, Vickers, or Brinell scales, and equivalent values to thoseof the Mohs scale may be used to characterize the aggregates of theinvention; e.g., a Vickers hardness rating of 250 corresponds to a Mohsrating of 3; conversions between the scales are known in the art.

The abrasion resistance of an aggregate may also be of significance,e.g., for use in a roadway surface, where aggregates of high abrasionresistance are useful to keep surfaces from polishing. Abrasionresistance is related to hardness but is not the same. Aggregatesinclude aggregates that have an abrasion resistance similar to that ofnatural limestone, or aggregates that have an abrasion resistancesuperior to natural limestone, as well as aggregates having an abrasionresistance lower than natural limestone, as measured by art acceptedmethods, such as ASTM C131-03. In some embodiments, aggregates made fromthe compositions of the invention have an abrasion resistance of lessthan 50%, or less than 40%, or less than 35%, or less than 30%, or lessthan 25%, or less than 20%, or less than 15%, or less than 10%, whenmeasured by ASTM C131-03.

Aggregates may also have a porosity within a particular ranges. As willbe appreciated by those of skill in the art, in some cases a highlyporous aggregate is desired, in others an aggregate of moderate porosityis desired, while in other cases aggregates of low porosity, or noporosity, are desired. Porosities of aggregates in some embodiments ofthe invention, as measured by water uptake after oven drying followed byfull immersion for 60 minutes, expressed as % dry weight, can be in therange of 1-40%, such as 2-20%, or 2-15%, including 2-10% or even 3-9%.

In addition, aggregates formed from the compositions of the inventionmay further include or exclude substances such as chloride. Thesesubstances are considered undesirable in some applications; for example,chloride is undesirable in aggregates intended for use in concretebecause of its tendency to corrode rebar. However, in some uses, such asbase course for a roadway, aggregate containing chloride may beacceptable. Methods of making aggregates from the compositions of theinvention may include one or more steps to minimize the chloride and/orsodium content of the aggregate, if chloride is a component of thestarting materials; in some embodiments, such a step or steps is notnecessary as the intended final use of the aggregate is relativelyinsensitive to the content of these materials. Thus, in someembodiments, the leachable chloride content of the aggregates of theinvention is less than 5%. In some embodiments, the leachable chloridecontent of the aggregate ranges from 0.0001% to 0.05%. In someembodiments the leachable chloride content is less than 0.05%, in someembodiments the leachable chloride content is les than 0.1%, and in someembodiments the leachable chloride content is less than 0.5%.

The aggregate of the invention may be of any size and shape suitable fora particular use, as described further herein. As the aggregates aresynthetic, both the size and the shape may be almost completelycontrolled, allowing for a great variety of specific aggregates as wellas aggregate mixes, as described further. In some embodiments, theinvention provides coarse aggregate, e.g., compositions that arepredominantly retained on a Number 4 sieve (ASTM C 125 and ASTM C 33).Coarse aggregate according to embodiments of the invention has anaverage particle size ranging from 0.125 in to 6 in, such as 0.187 in to3.0 in and including 0.25 in to 1.0 in. Fine aggregate according toembodiments of the invention has an average particle size ranging from0.001 inch (in) to 0.25 in, such as 0.05 in to 0.125 in and including0.01 in to 0.08 in.

Aggregates of the invention may be reactive or non-reactive. Reactiveaggregate are those aggregate particles that upon initiation by asubstance (e.g., water) undergo a reaction with constituents (e.g.,compounds) in other aggregate particles to form a reaction product. Insome instances, the reaction product may be a matrix between aggregateparticles forming a stabilizing structure. In other instances the matrixformed may be an expansive gel that, depending on the environment, mayact to destabilize the mass; in some cases where there is room for theexpansive gel to expand, e.g., in aggregate that is laid as part of aroad bed, with void spaces, a reactive aggregate of this type isacceptable. Aggregate of the invention may also be non-reactive.

In addition, in some instances the invention provides aggregates thatare resistant to acid, resistant to base, or resistant to both acid andbase. For example, in some instances the invention provides aggregatesthat, when exposed to a pH of 2, 3, 4, or 5, depending on the testdesired (e.g., an H₂SO₄ solution that has been diluted to a pH of 2, 3,4, or 5), release less than 1, 0.1, 0.01, or 0.001% of the CO₂ containedin the aggregate in a 48 hour period, or a 1-week period, or a 5-weekperiod, or a 25-week period, while remaining intact and retaining aportion or substantially all of its hardness, abrasion resistance, andthe like. Similar results may be obtained for aggregates of theinvention that are resistant to base, e.g., when exposed to a pH of 12,11, 10, or 9, release less than 1, 0.1, 0.01, or 0.001% of their CO₂ ina 48 hour, lweek, 5 week, or 25 week period, while remaining intact andretaining a portion or substantially all of its hardness, abrasionresistance, and the like. The aggregates may be ground to a standardsurface area or sieve size before conducting such tests. CO₂ content ofthe material may be monitored by, e.g., coulometry, or any othersuitable method.

The compositions of the invention made from CO₂ source may result in theCO₂-sequestering aggregate that may provide for long term storage of CO₂in a manner such that CO₂ is sequestered (i.e., fixed) in the aggregate,where the sequestered CO₂ does not become part of the atmosphere. “Longterm storage” includes that the aggregate of the invention keeps itssequestered CO₂ fixed for extended periods of time (when the aggregateis maintained under conditions conventional for its intended use)without significant, if any, release of the CO₂ from the aggregate.Extended periods of time in the context of the invention may be 1 yearor longer, 5 years or longer, 10 years or longer, 25 years or longer, 50years or longer, 100 years or longer, 250 years or longer, 1000 years orlonger, 10,000 years or longer, 1,000,000 years or longer, or even100,000,000 years or longer, depending on the particular nature anddownstream use of the aggregate. With respect to the CO₂ sequesteringaggregate, when employed for their intended use and over their lifetime,the amount of degradation, if any, as measured in terms of CO₂ gasrelease from the product will not exceed 10% per year, for example, willnot exceed 5%/year, and in certain embodiments will not exceed 1%/yearor even will not exceed 0.5% per year or even 0.1% per year.

Tests of the aggregate can be used as surrogate markers for thelong-term storage capability of the aggregate. Any art-accepted test maybe used, or any test that reasonably would be thought to predictlong-term storage of CO₂ in a material under its intended conditions ofuse may be used, e.g., any test that reasonably would be thought topredict that the composition keeps a significant fraction, orsubstantially all, of its CO₂ fixed for a certain amount of time. Forexample, aggregate may be considered long term storage aggregate forsequestered CO₂ if, when exposed to 50, 75, 90, 100, 120, or 150° C. for1, 2, 5, 25, 50, 100, 200, or 500 days at between 10% and 50% relativehumidity, it loses less than 1%, 2%, 3%, 4%, 5%, 10%, 20%, 30%, or 50%of its carbon. Test conditions are chosen according to the intended useand environment of the material. CO₂ content of the material may bemonitored by any suitable method, e.g., coulometry.

In some embodiments the invention provides a lightweight aggregate,e.g., an aggregate with a bulk density of 75-125 lb/ft³, or 90-115lb/ft³. The lightweight aggregate in some embodiments contains carbonateand sulfate or sulfite, or a combination of sulfate and sulfite. In someembodiments the molar ration of carbonate to sulfate and/or sulfite is1000:1 to 10:1, or 500:1 to 50:1, or 300:1 to 75:1. In some of theseembodiments, the aggregate further contains mercury or a mercurycompound, which may be of fossil fuel origin. In some embodiments, theaggregate contains dypingite.

In some embodiments, the invention provides a customized set ofaggregates, e.g., a set of aggregates with a plurality ofcharacteristics that is chosen to match a predetermined set ofcharacteristics, such as at least two, three, four, or five of size,shape, surface texture, hardness, abrasion resistance, density,porosity, acid stability, base stability, CO₂ release stability, andcolor. In some embodiments the invention provides a set of aggregateswith a plurality of characteristics that are chosen to match apredetermined set of characteristics, where the characteristics includesize, shape, and hardness. In some embodiments, the invention provides aset of aggregates with a plurality of characteristics that are chosen tomatch a predetermined set of characteristics, where the characteristicsinclude size, shape, hardness, and surface texture. In some embodimentsthe invention provides a set of aggregates with a plurality ofcharacteristics that are chosen to match a predetermined set ofcharacteristics, where the characteristics include size, shape,hardness, and density. In some embodiments, the invention provides a setof aggregates with a plurality of characteristics that are chosen tomatch a predetermined set of characteristics, where the characteristicsinclude size, shape, and density.

The aggregate may have particle shapes selected from the groupconsisting of: rounded, irregular, flaky, angular, elongated,flaky-elongated, subangular, subrounded, well rounded and any mixturesthereof; in some cases the aggregate further has particle surfacetextures that are selected from the group consisting of: glassy, smooth,granular, rough, crystalline, honeycombed and mixtures thereof. In someembodiments, the aggregate has particle shapes selected from the groupconsisting of: polygonal, cylindrical, spherical, triangular, curvedshapes, annulus, ellipsoidal, oval, star shaped, prisms or any mixturesthereof; and in some cases may further have particle surface texturesthat are selected from the group consisting of: glassy, smooth,granular, rough, crystalline, honeycombed and mixtures thereof. Theaggregate may have a Mohs hardness that ranges from about 1 to 9, suchas about 2 to 6, or equivalent hardness on the Rockwell, Vickers, orBrinell scales. Any of the above aggregates may further include one ormore of: Portland cement, fly ash, lime and a binder, for example,Portland cement, such as where the weight ratio of the syntheticcarbonate:Portland cement ranges from 0.1/1 to 5/1. The aggregate has aunit density of between 100 to 150 lb/ft³, such as between 75-125lb/ft³.

In some embodiments, the invention provides an aggregate suitable foruse in a building material wherein the aggregate has a unit density ofless than 115 lb/cu ft and is a carbon negative aggregate.

In some embodiments, the invention provides road base includingaggregate made from the compositions of the invention, described herein.In some embodiments, the invention provides an asphalt includingaggregate made from the compositions of the invention, described herein.

In some embodiments, the invention provides a concoidally-fracturingaggregate.

II. Methods and Systems

Aspects of the invention include methods and systems for making thecomposition of the invention. The method to produce the compositions ofthe invention include a source of carbon, a source of water, a source ofalkalinity, and a source for alkaline earth metal ions, depending uponthe materials used for the process. In one aspect of the invention,there is provided a method for making the composition provided herein,by (a) contacting an alkaline earth-metal containing water with a fluegas from an industrial plant including carbon of a fossil fuel origin;and (b) subjecting the alkaline earth-metal containing water of step (a)to one or more conditions to make the composition of the invention.

In another aspect of the invention, there is provided a method formaking a composition by (a) contacting an alkaline earth-metalcontaining water with a CO₂ source; and (b) subjecting the alkalineearth-metal containing water of step (a) to one or more conditions tomake a composition, wherein the composition comprises at least 47% w/wvaterite and wherein the composition upon combination with water,setting, and hardening has a compressive strength of at least 14 MPa.

Source of Carbon

The CO₂ source may be a liquid, solid (e.g., dry ice) or gaseous CO₂source. In certain embodiments, the CO₂ source is a gaseous CO₂ source.This gaseous CO₂ is, in certain instances, a waste stream or productfrom an industrial plant. The nature of the industrial plant may vary inthese embodiments, where industrial plants of interest includes, but isnot limited to, power plants (e.g., as described in further detail inInternational Application No. PCT/US08/88318, titled, “METHODS OFSEQUESTERING CO₂,” filed 24 Dec. 2008, the disclosure of which is hereinincorporated by reference), chemical processing plants, steel mills,paper mills, cement plants (e.g., as described in further detail in U.S.Provisional Application Ser. No. 61/088,340, the disclosure of which isherein incorporated by reference), and other industrial plants thatproduce CO₂ as a byproduct. By waste stream is meant a stream of gas (oranalogous stream) that is produced as a byproduct of an active processof the industrial plant. The gaseous stream may be substantially pureCO₂ or a multi-component gaseous stream that includes CO₂ and one ormore additional gases. Multi-component gaseous streams (containing CO₂)that may be employed as a CO₂ source in embodiments of the subjectmethods include both reducing, e.g., syngas, shifted syngas, naturalgas, and hydrogen and the like, and oxidizing condition streams, e.g.,flue gases from combustion. Exhaust gases containing NOx, SOx, VOCs,particulates and Hg would incorporate these compounds along with thecarbonate in the precipitated product. Particular multi-componentgaseous streams of interest that may be treated according to the subjectinvention include, but are not limited to, oxygen containing combustionpower plant flue gas, turbo charged boiler product gas, coalgasification product gas, shifted coal gasification product gas,anaerobic digester product gas, wellhead natural gas stream, reformednatural gas or methane hydrates, and the like.

Thus, the waste streams may be produced from a variety of differenttypes of industrial plants. Suitable waste streams for the inventioninclude waste streams, such as, flue gas, produced by industrial plantsthat combust fossil fuels (e.g., coal, oil, natural gas) oranthropogenic fuel products of naturally occurring organic fuel deposits(e.g., tar sands, heavy oil, oil shale, etc.). In some embodiments, awaste stream suitable for systems and methods of the invention issourced from a coal-fired power plant, such as a pulverized coal powerplant, a supercritical coal power plant, a mass burn coal power plant, afluidized bed coal power plant. In some embodiments, the waste stream issourced from gas or oil-fired boiler and steam turbine power plants, gasor oil-fired boiler simple cycle gas turbine power plants, or gas oroil-fired boiler combined cycle gas turbine power plants. In someembodiments, waste streams produced by power plants that combust syngas(i.e., gas that is produced by the gasification of organic matter, forexample, coal, biomass, etc.) are used. In some embodiments, wastestreams from integrated gasification combined cycle (IGCC) plants areused. In some embodiments, waste streams produced by Heat Recovery SteamGenerator (HRSG) plants are used to produce compositions in accordancewith systems and methods of the invention.

Waste streams produced by cement plants are also suitable for systemsand methods of the invention. Cement plant waste streams include wastestreams from both wet process and dry process plants, which plants mayemploy shaft kilns or rotary kilns, and may include pre-calciners. Theseindustrial plants may each burn a single fuel, or may burn two or morefuels sequentially or simultaneously.

In some embodiments, the source of carbon is synthetic or naturallyoccurring carbonate, such as sodium carbonate, or limestone.

Source of Water

As reviewed above, “saltwater” is employed in its conventional sense toinclude a number of different types of aqueous fluids other than freshwater, where the term “saltwater” includes brackish water, sea water andbrine (including man-made brines, e.g., geothermal plant wastewaters,desalination waste waters, etc), as well as other salines having asalinity that is greater than that of freshwater. Brine is watersaturated or nearly saturated with salt and has a salinity that is 50ppt (parts per thousand) or greater. Brackish water is water that issaltier than fresh water, but not as salty as seawater, having asalinity ranging from 0.5 to 35 ppt. Seawater is water from a sea orocean and has a salinity ranging from 35 to 50 ppt.

The saltwater source from which the composition of the invention isderived may be a naturally occurring source, such as a sea, ocean, lake,swamp, estuary, lagoon, etc., or a man-made source. The compositions ofthe invention may be produced by precipitation fromalkaline-earth-metal-containing water, such as, a saltwater (may becalled saltwater derived composition), or a freshwater with addedalkaline earth metal ions. The saltwater employed in methods may vary.

In some embodiments, the water employed in the invention may be amineral rich, e.g., calcium and/or magnesium rich, freshwater source. Insome embodiments, calcium rich waters may be combined with magnesiumsilicate minerals, such as olivine or serpentine. The acidity in thesolution, due to the addition of carbon dioxide to form carbonic acid,may dissolve the magnesium silicate, leading to the formation of calciummagnesium silicate carbonate compounds.

In some embodiments, the compositions are obtained from a saltwater insome manner, e.g., by treating a volume of a saltwater in a mannersufficient to produce the desired composition of the invention from theinitial volume of saltwater. In certain embodiments, the compositions ofthe invention are derived from saltwater by precipitating them from thesaltwater. In certain embodiments, the compositions of the invention areseparated in a solid form from the saltwater. The compositions of theinvention may be more stable in salt water than in freshwater, such thatthey may be viewed as saltwater metastable compositions.

In certain embodiments, the water may be obtained from the power plantthat is also providing the gaseous waste stream. For example, in watercooled power plants, such as seawater cooled power plants, water thathas been employed by the power plant may then be sent to theprecipitation system and employed as the water in the precipitationreaction. In certain of these embodiments, the water may be cooled priorto entering the precipitation reactor.

Source of Alkalinity

In order to produce carbonate-containing precipitation material, protonsare removed from various species (e.g. carbonic acid, bicarbonate,hydronium, etc.) in the divalent cation-containing solution to shift theequilibrium towards carbonate. The terms “source of alkalinity” or“proton removing agents” or “pH raising agent,” or “base,” are usedinterchangeably herein. As protons are removed, more CO₂ goes intosolution. In some embodiments, proton-removing agents and/or methods areused while contacting a divalent cation-containing aqueous solution withCO₂ to increase CO₂ absorption in one phase of the precipitationreaction, wherein the pH may remain constant, increase, or evendecrease, followed by a rapid removal of protons (e.g., by addition of abase) to cause rapid precipitation of carbonate-containing precipitationmaterial. Protons may be removed from the various species (e.g. carbonicacid, bicarbonate, hydronium, etc.) by any suitable approach, including,but not limited to, use of naturally occurring proton-removing agents,use of microorganisms and fungi, use of synthetic chemicalproton-removing agents, recovery of man-made waste streams, and usingelectrochemical means.

Naturally occurring proton-removing agents encompass any proton-removingagents that can be found in the wider environment that may create orhave a basic local environment. Some embodiments provide for naturallyoccurring proton-removing agents including minerals that create basicenvironments upon addition to solution. Such minerals include, but arenot limited to, lime (CaO); periclase (MgO); iron hydroxide minerals(e.g., goethite and limonite); and volcanic ash. Methods for digestionof such minerals and rocks including such minerals are well known in theart.

Many minerals provide sources of divalent cations and, in addition, someminerals are sources of base. Mafic and ultramafic minerals such asolivine, serpentine, and any other suitable mineral may be dissolvedusing any convenient protocol. Dissolution may be accelerated byincreasing surface area, such as by milling by conventional means or by,e.g., jet milling, as well as by use of, e.g., ultrasonic techniques. Inaddition, mineral dissolution may be accelerated by exposure to acid orbase. Metal silicates (e.g., magnesium silicates) and other mineralsincluding cations of interest may be dissolved, e.g., in acid (e.g., HClsuch as HCl from an electrochemical process) to produce, for example,magnesium and other metal cations for use in precipitation material,and, subsequently, compositions of the invention. In some embodiments,magnesium silicates and other minerals may be digested or dissolved inan aqueous solution that has become acidic due to the addition of carbondioxide and other components of waste gas (e.g., combustion gas).Alternatively, other metal species such as metal hydroxide (e.g.,Mg(OH)₂, Ca(OH)₂) may be made available for use in aggregate bydissolution of one or more metal silicates (e.g., olivine andserpentine) with aqueous alkali hydroxide (e.g., NaOH) or any othersuitable caustic material. Any suitable concentration of aqueous alkalihydroxide or other caustic material may be used to decompose metalsilicates, including highly concentrated and very dilute solutions. Theconcentration (by weight) of an alkali hydroxide (e.g., NaOH) insolution may be, for example, from 30% to 80% and from 70% to 20% water.Advantageously, metal silicates and the like digested with aqueousalkali hydroxide may be used directly to produce precipitation material,and, subsequently, aggregate from a waste gas stream. In addition, basevalue from the precipitation reaction mixture may be recovered andreused to digest additional metal silicates and the like.

Some embodiments provide for using naturally alkaline bodies of water asnaturally occurring proton-removing agents. Examples of naturallyalkaline bodies of water include, but are not limited to surface watersources (e.g. alkaline lakes such as Mono Lake in California) and groundwater sources (e.g. basic aquifers such as the deep geologic alkalineaquifers located at Searles Lake in California). Other embodimentsprovide for use of deposits from dried alkaline bodies of water such asthe crust along Lake Natron in Africa's Great Rift Valley.

In some embodiments, organisms that excrete basic molecules or solutionsin their normal metabolism are used as proton-removing agents. Examplesof such organisms are fungi that produce alkaline protease (e.g., thedeep-sea fungus Aspergillus ustus with an optimal pH of 9) and bacteriathat create alkaline molecules (e.g., cyanobacteria such as Lyngbya sp.from the Atlin wetland in British Columbia, which increases pH from abyproduct of photosynthesis). In some embodiments, organisms are used toproduce proton-removing agents, wherein the organisms (e.g., Bacilluspasteurii, which hydrolyzes urea to ammonia) metabolize a contaminant(e.g. urea) to produce proton-removing agents or solutions includingproton-removing agents (e.g., ammonia, ammonium hydroxide). In someembodiments, organisms are cultured separately from the precipitationreaction mixture, wherein proton-removing agents or solution includingproton-removing agents are used for addition to the precipitationreaction mixture. In some embodiments, naturally occurring ormanufactured enzymes are used in combination with proton-removing agentsto invoke precipitation of precipitation material. Carbonic anhydrase,which is an enzyme produced by plants and animals, acceleratestransformation of carbonic acid to bicarbonate in aqueous solution.

Chemical agents for effecting proton removal generally refer tosynthetic chemical agents that are produced in large quantities and arecommercially available. For example, chemical agents for removingprotons include, but are not limited to, hydroxides, organic bases,super bases, oxides, ammonia, and carbonates. Hydroxides includechemical species that provide hydroxide anions in solution, including,for example, sodium hydroxide (NaOH), potassium hydroxide (KOH), calciumhydroxide (Ca(OH)₂), or magnesium hydroxide (Mg(OH)₂). Organic bases arecarbon-containing molecules that are generally nitrogenous basesincluding primary amines such as methyl amine, secondary amines such asdiisopropylamine, tertiary such as diisopropylethylamine, aromaticamines such as aniline, heteroaromatics such as pyridine, imidazole, andbenzimidazole, and various forms thereof. In some embodiments, anorganic base selected from pyridine, methylamine, imidazole,benzimidazole, histidine, and a phophazene is used to remove protonsfrom various species (e.g., carbonic acid, bicarbonate, hydronium, etc.)for precipitation of precipitation material. In some embodiments,ammonia is used to raise pH to a level sufficient to precipitateprecipitation material from a solution of divalent cations and anindustrial waste stream. Super bases suitable for use as proton-removingagents include sodium ethoxide, sodium amide (NaNH₂), sodium hydride(NaH), butyl lithium, lithium diisopropylamide, lithium diethylamide,and lithium bis(trimethylsilyl)amide. Oxides including, for example,calcium oxide (CaO), magnesium oxide (MgO), strontium oxide (SrO),beryllium oxide (BeO), and barium oxide (BaO) are also suitableproton-removing agents that may be used. Carbonates for use in theinvention include, but are not limited to, sodium carbonate.

In addition to including cations of interest and other suitable metalforms, waste streams from various industrial processes may provideproton-removing agents. Such waste streams include, but are not limitedto, mining wastes; fossil fuel burning ash (e.g., combustion ash such asfly ash, bottom ash, boiler slag); slag (e.g. iron slag, phosphorousslag); cement kiln waste; oil refinery/petrochemical refinery waste(e.g. oil field and methane seam brines); coal seam wastes (e.g. gasproduction brines and coal seam brine); paper processing waste; watersoftening waste brine (e.g., ion exchange effluent); silicon processingwastes; agricultural waste; metal finishing waste; high pH textilewaste; and caustic sludge. Mining wastes include any wastes from theextraction of metal or another precious or useful mineral from theearth. In some embodiments, wastes from mining are used to modify pH,wherein the waste is selected from red mud from the Bayer aluminumextraction process; waste from magnesium extraction from sea water(e.g., Mg(OH)₂ such as that found in Moss Landing, Calif.); and wastesfrom mining processes involving leaching. For example, red mud may beused to modify pH as described in U.S. Provisional Patent ApplicationNo. 61/161,369, titled, “NEUTRALIZING INDUSTRIAL WASTES UTILIZING CO₂AND A DIVALENT CATION SOLUTION”, filed 18 Mar. 2009, which is herebyincorporated by reference in its entirety. Fossil fuel burning ash,cement kiln dust, and slag, collectively waste sources of metal oxides,further described in U.S. patent application Ser. No. 12/486,692,titled, “METHODS AND SYSTEMS FOR UTILIZING WASTE SOURCES OF METALOXIDES,” filed 17 Jun. 2009, the disclosure of which is incorporatedherein in its entirety, may be used in alone or in combination withother proton-removing agents to provide proton-removing agents for theinvention. Agricultural waste, either through animal waste or excessivefertilizer use, may contain potassium hydroxide (KOH) or ammonia (NH₃)or both. As such, agricultural waste may be used in some embodiments ofthe invention as a proton-removing agent. This agricultural waste isoften collected in ponds, but it may also percolate down into aquifers,where it can be accessed and used.

Where desired, the pH of the water is raised using any convenient and/orsuitable approach. In certain embodiments, a pH raising agent may beemployed, where examples of such agents include oxides, hydroxides(e.g., sodium hydroxide, potassium hydroxide, brucite), carbonates (e.g.sodium carbonate), coal ash, naturally occurring mineral, and the like.The amount of pH elevating agent that is added to the saltwater sourcewill depend on the particular nature of the agent and the volume ofsaltwater being modified, and will be sufficient to raise the pH of thesalt water source to the desired value. Alternatively, the pH of thesaltwater source can be raised to the desired level by electrolysis ofthe water.

One such approach can be to use the coal ash from a coal-fired powerplant, which contains many oxides, to elevate the pH of sea water. Othercoal processes, like the gasification of coal, to produce syngas, alsoproduce hydrogen gas and carbon monoxide, and may serve as a source ofhydroxide as well. Some naturally occurring minerals, such as,serpentine contain hydroxide, and can be dissolved, yielding a hydroxidesource. The amount of pH elevating agent that is added to the water willdepend on the particular nature of the agent and the volume of saltwaterbeing modified, and will be sufficient to raise the pH of the water tothe desired value. Alternatively, the pH of the saltwater source can beraised to the desired level by electrolysis of the water. Whereelectrolysis is employed, a variety of different protocols may be taken,such as use of the Mercury cell process (also called the Castner-Kellnerprocess); the Diaphragm cell process and the membrane cell process.Where desired, byproducts of the hydrolysis product, e.g., H₂, sodiummetal, etc. may be harvested and employed for other purposes, asdesired.

Electrochemical methods are another means to remove protons from variousspecies in a solution, either by removing protons from solute (e.g.,deprotonation of carbonic acid or bicarbonate) or from solvent (e.g.,deprotonation of hydronium or water). Deprotonation of solvent mayresult, for example, if proton production from CO₂ dissolution matchesor exceeds electrochemical proton removal from solute molecules. In someembodiments, low-voltage electrochemical methods are used to removeprotons, for example, as CO₂ is dissolved in the precipitation reactionmixture or a precursor solution to the precipitation reaction mixture(i.e., a solution that may or may not contain divalent cations).

In some embodiments, CO₂ dissolved in an aqueous solution that does notcontain divalent cations is treated by a low-voltage electrochemicalmethod to remove protons from carbonic acid, bicarbonate, hydronium, orany species or combination thereof resulting from the dissolution ofCO₂. A low-voltage electrochemical method operates at an average voltageof 2, 1.9, 1.8, 1.7, or 1.6 V or less, such as 1.5, 1.4, 1.3, 1.2, 1.1 Vor less, such as 1 V or less, such as 0.9 V or less, 0.8 V or less, 0.7V or less, 0.6 V or less, 0.5 V or less, 0.4 V or less, 0.3 V or less,0.2 V or less, or 0.1 V or less. Low-voltage electrochemical methodsthat do not generate chlorine gas are convenient for use in systems andmethods of the invention. Low-voltage electrochemical methods to removeprotons that do not generate oxygen gas are also convenient for use insystems and methods of the invention. In some embodiments, low-voltageelectrochemical methods generate hydrogen gas at the cathode andtransport it to the anode where the hydrogen gas is converted toprotons. Electrochemical methods that do not generate hydrogen gas mayalso be convenient. In some embodiments, electrochemical processes toremove protons do not generate a gas at the anode. In some instances,electrochemical methods to remove protons do not generate any gaseousby-byproduct.

Electrochemical methods for effecting proton removal are furtherdescribed in U.S. patent application Ser. No. 12/344,019, titled,“METHODS OF SEQUESTERING CO₂,” filed 24 Dec. 2008; U.S. patentapplication Ser. No. 12/375,632, titled, “Low Energy ElectrochemicalHydroxide System and Method,” filed 23 Dec. 2008; International PatentApplication No. PCT/US08/088242, titled, “LOW ENERGY ELECTROMECHANICALHYDROXIDE SYSTEM AND METHOD,” filed 23 Dec. 2008; International PatentApplication No. PCT/US09/32301, titled, “LOW-ENERGY ELECTROCHEMICALBICARBONATE ION SOLUTION,” filed 28 Jan. 2009; and International PatentApplication No. PCT/US09/48511, titled, “LOW-ENERGY 4-CELLELECTROCHEMICAL SYSTEM WITH CARBON DIOXIDE GAS,” filed 24 Jun. 2009,each of which are incorporated herein by reference in their entirety.

Low voltage electrochemical processes may produce hydroxide at thecathode and protons at the anode; where such processes utilize a saltcontaining chloride, e.g. NaCl, a product of the process will be HCl.

Alternatively, electrochemical methods may be used to produce causticmolecules (e.g., hydroxide) through, for example, the chlor-alkaliprocess, or modification thereof. Electrodes (i.e., cathodes and anodes)may be present in the apparatus containing the divalentcation-containing aqueous solution or gaseous waste stream-charged(e.g., CO₂-charged) solution, and a selective barrier, such as amembrane, may separate the electrodes. Electrochemical systems andmethods for removing protons may produce by-products (e.g., hydrogen)that may be harvested and used for other purposes. Additionalelectrochemical approaches that may be used in systems and methods ofthe invention include, but are not limited to, those described in U.S.patent application Ser. No. 12/503,557, titled, “CO₂ UTILIZATION INELECTROCHEMICAL SYSTEMS,” filed 15 Jul. 2009 and U.S. ProvisionalApplication No. 61/091,729, titled, “LOW ENERGY ABSORPTION OF HYDROGENION FROM AN ELECTROLYTE SOLUTION INTO A SOLID MATERIAL,” filed 11 Sep.2008, the disclosures of which are herein incorporated by reference intheir entirety.

Combinations of the above mentioned sources of proton removal may beemployed. One such combination is the use of a microorganisms andelectrochemical systems. Combinations of microorganisms andelectrochemical systems include microbial electrolysis cells, includingmicrobial fuel cells, and bio-electrochemically assisted microbialreactors. In such microbial electrochemical systems, microorganisms(e.g. bacteria) are grown on or very near an electrode and in the courseof the metabolism of material (e.g. organic material) electrons aregenerated that are taken up by the electrode.

Additives other than pH elevating agents may also be introduced into thewater in order to influence the nature of the precipitate that isproduced. As such, certain embodiments of the methods include providingan additive in water before or during the time when the water issubjected to the precipitation conditions. Certain calcium carbonatepolymorphs can be favored by trace amounts of certain additives, suchas, but are not limited to, lanthanum as lanthanum chloride, transitionmetals, iron, nickel, and the like. For instance, iron may favor theformation of disordered dolomite (protodolomite).

In some embodiments, the source of alkalinity is a bicarbonate,carbonate, or a mixture of NaOH and carbon dioxide, and the alkalinesolution is a “high carbonate” alkaline solution. By “high carbonate”alkaline solution is meant an aqueous composition which possessescarbonate in a sufficient amount so as to remove one or more protonsfrom proton-containing species in solution such that carbonic acid isconverted to bicarbonate. As such, the amount of carbonate present inalkaline solutions of the invention may be 5,000 ppm or greater, such as10,000 ppm greater, such as 25,000 ppm or greater, such as 50,000 ppm orgreater, such as 75,000 ppm or greater, including 100,000 ppm orgreater.

Source of Cations, Such as, Alkaline Earth Metals

The source of cations, such as sodium, potassium, or alkaline earthmetal ions etc., is any aqueous medium containing alkaline earth metals,such as, but are not limited to, calcium, magnesium, strontium, barium,etc. or combination thereof. In some embodiments, the alkaline earthmetal is calcium, magnesium, or combination thereof and the source ofalkaline earth metal is any aqueous medium containing calcium, magnesiumor combination thereof. In some embodiments, alkaline earth metal sourceis also the source of water and/or source of alkalinity, as describedherein. For example, the aqueous solution of alkaline earth metal ionsmay comprise cations derived from freshwater, brackish water, seawater,or brine (e.g., naturally occurring subterranean brines or anthropogenicsubterranean brines such as geothermal plant wastewaters, desalinationplant waste waters), as well as other salines having a salinity that isgreater than that of freshwater, any of which may be naturally occurringor anthropogenic.

Divalent cations (e.g., alkaline earth metal cations such as Ca²⁺ andMg²⁺), which are useful for producing precipitation material of theinvention, may be found in industrial wastes, seawater, brines, hardwater, minerals, and many other suitable sources.

In some locations, industrial waste streams from various industrialprocesses provide for convenient sources of cations (as well as in somecases other materials useful in the process, e.g., metal hydroxide).Such waste streams include, but are not limited to, mining wastes;fossil fuel burning ash (e.g., fly ash, bottom ash, boiler slag); slag(e.g., iron slag, phosphorous slag); cement kiln waste (e.g., cementkiln dust); oil refinery/petrochemical refinery waste (e.g., oil fieldand methane seam brines); coal seam wastes (e.g., gas production brinesand coal seam brine); paper processing waste; water softening wastebrine (e.g., ion exchange effluent); silicon processing wastes;agricultural waste; metal finishing waste; high pH textile waste; andcaustic sludge.

In some locations, a convenient source of cations for use in systems andmethods of the invention is water (e.g., an aqueous solution includingcations such as seawater or subterranean brine), which may varydepending upon the particular location at which the invention ispracticed. Suitable aqueous solutions of cations that may be usedinclude solutions including one or more divalent cations, e.g., alkalineearth metal cations such as Ca²⁺ and Mg²⁺. In some embodiments, theaqueous source of cations comprises alkaline earth metal cations. Insome embodiments, the alkaline earth metal cations include calcium,magnesium, or a mixture thereof. In some embodiments, the aqueoussolution of cations comprises calcium in amounts ranging from 50 to50,000 ppm, 50 to 40,000 ppm, 50 to 20,000 ppm, 100 to 10,000 ppm, 200to 5000 ppm, or 400 to 1000 ppm, or 10,000 to 50,000 ppm, or 20,000 to50,000 ppm, or 20,000 to 30,000 ppm.

In some embodiments, mineral rich freshwater may be a convenient sourceof cations (e.g., cations of alkaline earth metals such as Ca²⁻ andMg²⁺). Any of a number of suitable freshwater sources may be used,including freshwater sources ranging from sources relatively free ofminerals to sources relatively rich in minerals. Mineral-rich freshwatersources may be naturally occurring, including any of a number of hardwater sources, lakes, or inland seas. Some mineral-rich freshwatersources such as alkaline lakes or inland seas (e.g., Lake Van in Turkey)also provide a source of pH-modifying agents. Mineral-rich freshwatersources may also be anthropogenic. For example, a mineral-poor (soft)water may be contacted with a source of cations such as alkaline earthmetal cations (e.g., Ca²⁻, Mg²⁺, etc.) to produce a mineral-rich waterthat is suitable for methods and systems described herein. Cations orprecursors thereof (e.g., salts, minerals) may be added to freshwater(or any other type of water described herein) using any convenientprotocol (e.g., addition of solids, suspensions, or solutions). In someembodiments, divalent cations selected from Ca²⁺ and Mg²⁺ are added tofreshwater. In some embodiments, monovalent cations selected from Na⁺and K⁺ are added to freshwater. In some embodiments, freshwaterincluding Ca²⁻ is combined with magnesium silicates (e.g., olivine orserpentine), or products or processed forms thereof, yielding a solutionincluding calcium and magnesium cations.

Many minerals provide sources of cations and, in addition, some mineralsare sources of base. Divalent cation-containing minerals include maficand ultramafic minerals such as olivine, serpentine, and other suitableminerals, which may be dissolved using any convenient protocol. In oneembodiment, cations such as calcium may be provided for methods andcompositions of this invention from feldspars such as anorthite. Cationsmay be obtained directly from mineral sources or from subterraneanbrines, high in calcium or other divalent cations. Other minerals suchas wollastonite may also be used. Dissolution may be accelerated byincreasing surface area, such as by milling by conventional means or by,for example, jet milling, as well as by use of, for example, ultrasonictechniques. In addition, mineral dissolution may be accelerated byexposure to acid or base.

Metal silicates (e.g., magnesium silicates) and other minerals includingcations of interest may be dissolved, for example, in acid such as HCl(optionally from an electrochemical process) to produce, for example,magnesium and other metal cations for use in compositions of theinvention. In some embodiments, magnesium silicates and other mineralsmay be digested or dissolved in an aqueous solution that has becomeacidic due to the addition of carbon dioxide and other components ofwaste gas (e.g., combustion gas). Alternatively, other metal speciessuch as metal hydroxide (e.g., Mg(OH)₂, Ca(OH)₂) may be made availablefor use by dissolution of one or more metal silicates (e.g., olivine andserpentine) with aqueous alkali hydroxide (e.g., NaOH) or any othersuitable caustic material. Any suitable concentration of aqueous alkalihydroxide or other caustic material may be used to decompose metalsilicates, including highly concentrated and very dilute solutions. Theconcentration (by weight) of an alkali hydroxide (e.g., NaOH) insolution may be, for example, from 30% to 80% (w/w).

Brines

As used herein, “brines” includes synthetic brines or naturallyoccurring brines, such as, but are not limited to subterranean brines.The brines may provide the source of water, the source of alkaline earthmetal ions, the source of carbon or carbonate, the source of alkalinity,or combinations thereof.

In some embodiments the subterranean brines of this invention may be aconvenient source for divalent cations, monovalent cations, protonremoving agents, or any combination thereof. The subterranean brine thatis employed in embodiments of the invention may be from any convenientsubterranean brine source. “Subterranean brine” is employed in itsconventional sense to include naturally occurring or anthropogenic,concentrated aqueous saline compositions obtained from a geologicallocation. The geological location of the subterranean brine can be foundbelow ground (subterranean geological location), on the surface, orsubsurface of the lakes. Concentrated aqueous saline compositionincludes an aqueous solution which has a salinity of 10,000 ppm totaldissolved solids (TDS) or greater, such as 20,000 ppm TDS or greater andincluding 50,000 ppm TDS or greater. Subterranean geological locationincludes a geological location which is located below ground level, suchas, a solid-fluid interface of the Earth's surface, such as a solid-gasinterface as found on dry land where dry land meets the Earth'satmosphere, as well as a liquid-solid interface as found beneath a bodyof surface water (e.g., lack, ocean, stream, etc) where solid groundmeets the body of water (where examples of this interface include lakebeds, ocean floors, etc). For example, the subterranean location can bea location beneath land or a location beneath a body of water (e.g.,oceanic ridge). For example, a subterranean location may be a deepgeological alkaline aquifer or an underground well located in thesedimentary basins of a petroleum field, a subterranean metal ore, ageothermal field, or an oceanic ridge, among other undergroundlocations.

Brines may be concentrated waste streams from wastewater treatmentplants. In some embodiments, brines of this invention may be waterresulting from dissolution of mineral sources (e.g., oil and gasexploration or extraction) that has been concentrated or otherwisetreated. The waste streams from underground sources such as gas orpetroleum mining may contain hydrocarbons, carbonates, cations oranions. Treatment of these waste streams to reduce hydrocarbons and thewater volume may result in an aqueous mixture rich in carbonates,salinity, alkalinity or any combination thereof. This aqueous mixturemay be used to sequester carbon dioxide or may be used to precipitatehydrated carbon species such as carbonic acid, bicarbonate, orcarbonates.

The subterranean location may be a location that is 100 m or deeperbelow ground level, such as 200 m or deeper below ground level, such as300 m or deeper below ground level, such as 400 m or deeper below groundlevel, such as 500 m or deeper below ground level, such as 600 m ordeeper below ground level, such as 700 m or deeper below ground level,such as 800 m or deeper below ground level, such as 900 m or deeperbelow ground level, such as 1000 m or deeper below ground level,including 1500 m or deeper below ground level, 2000 m or deeper belowground level, 2500 m or deeper below ground level and 3000 m or deeperbelow ground level. In some embodiments of the invention, a subterraneanlocation is a location that is between 100 m and 3500 m below groundlevel, such as between 200 m and 2500 m below ground level, such asbetween 200 m and 2000 m below ground level, such as between 200 m and1500 m below ground level, such as between 200 m and 1000 m below groundlevel and including between 200 m and 800 m below ground level.Subterranean brines of the invention may include, but are not limitedto, oil-field brines, basinal brines, basinal water, pore water,formation water, and deep sea hypersaline waters, among others.

Subterranean brines of the invention may be subterranean aqueous salinecompositions and in some embodiments, may have circulated throughcrustal rocks and become enriched in substances leached from thesurrounding mineral. As such, the composition of subterranean brines mayvary. In some embodiments, the subterranean brines provide a source ofcations. The cations may be monovalent cations, such as Na⁺, K⁻, etc.The cations may also be divalent cations, such as Ca²⁺, Mg²⁺, Sr²⁺,Ba²⁺, Mn²⁺, Zn²⁺, Fe²⁺, etc. In some instances, the divalent cations ofthe subterranean brine are alkaline earth metal cations, e.g., Ca²⁺,Mg²⁺. Subterranean brines of interest may have Ca²⁺ present in amountsthat vary, ranging from 50 to 100,000 ppm, such as 100 to 75,000 ppm,including 500 to 50,000 ppm, for example 1000 to 25,000 ppm.Subterranean brines of interest may have Mg²⁺ present in amounts thatvary, ranging from 50 to 25,000 ppm, such as 100 to 15,000 ppm,including 500 to 10,000 ppm, for example 1000 to 5,000 ppm. In brineswhere both Ca²⁺ and Mg²⁺ are present, the molar ratio of Ca²⁺ to Mg²⁺(i.e., Ca²⁺:Mg²⁺) in the subterranean brine may vary, and in oneembodiment may range between 1:1 and 100:1. In some instance theCa²⁺:Mg²⁺ may be between 1:1 and 1:2.5; 1:2.5 and 1:5; 1:5 and 1:10;1:10 and 1:25; 1:25 and 1:50; 1:50 and 1:100; 1:100 and 1:150; 1:150 and1:200; 1:200 and 1:250; 1:250 and 1:500; 1:500 and 1:1000, or a rangethereof. For example, the molar ratio of Ca²⁺ to Mg²⁺ in subterraneanbrines of interest may range between 1:1 and 1:10; 1:5 and 1:25; 1:10and 1:50; 1:25 and 1:100; 1:50 and 1:500; or 1:100 and 1:1000. In someembodiments, the ratio of Mg²⁺ to Ca²⁺ (i.e., Mg²⁺:Ca²⁺) in thesubterranean brine ranges between 1:1 and 1:2.5; 1:2.5 and 1:5; 1:5 and1:10; 1:10 and 1:25; 1:25 and 1:50; 1:50 and 1:100; 1:100 and 1:150;1:150 and 1:200; 1:200 and 1:250; 1:250 and 1:500; 1:500 and 1:1000, ora range thereof. For example, the ratio of Mg²⁺ to Ca²⁺ in thesubterranean brines of interest may range between 1:1 and 1:10; 1:5 and1:25; 1:10 and 1:50; 1:25 and 1:100; 1:50 and 1:500; or 1:100 and1:1000. In particular embodiments the Mg²⁺:Ca²⁺ of a brine may be lowerthan 1:1, such as 1:2, 1:4, 1:10, 1:100 or lower.

In some embodiments, subterranean brines of the invention provide asource of alkalinity and contain proton-removing agents. Proton-removingagent includes a substance or compound which possesses sufficientalkalinity or basicity to remove one or more protons from aproton-containing species in solution. In some embodiments, the amountof proton-removing agent is an amount such that the subterranean brinepossesses a neutral pH (i.e., pH=7). In these embodiments, thestoichiometric sum of proton-removing agents is equal to thestoichiometric sum of proton-containing agents in the subterraneanbrine. The stoichiometric sum of proton-removing agents is the sum ofall substances or compounds (e.g., halides, oxyanions, organic bases,etc.) which can remove one or more protons from a proton-containingspecies in solution. In other embodiments, the amount of proton-removingagents in the subterranean brine is an amount such that the subterraneanbrine is alkaline. By alkaline is meant the stoichiometric sum ofproton-removing agents in the subterranean brine exceeds thestoichiometric sum of proton-containing agents. In some instances, thealkaline subterranean brine has a pH that is above neutral pH (i.e.,pH>7), e.g., the brine has a pH ranging from 7.1 to 12, such as 8 to 12,such as 8 to 11, and including 9 to 11. In some embodiments, asdescribed in greater detail below, while being basic the pH of thesubterranean brine may be insufficient to cause precipitation of thecarbonate-compound precipitation material. For example, the pH of thesubterranean brine may be 9.5 or lower, such as 9.3 or lower, including9 or lower.

Proton-removing agents present in subterranean brines of the inventionmay vary. In some embodiments, the proton-removing agents may be anions.Anions may be halides, such as Cl⁻, F⁻, I⁻ and Br⁻, among others andoxyanions, e.g., sulfate, carbonate, borate and nitrate, among others.

In some embodiments, the proton-removing agent is borate. Boratespresent in subterranean brines of the invention may be any oxyanion ofboron, e.g., BO₃ ³⁻, B₂O₅ ⁴⁻, B₃O₇ ⁵⁻, and B₄O₉ ⁶⁻, among others. Theamount of borate present in subterranean brines of the invention mayvary. In some instances, the amount of borate present ranges from 50 to100,000 ppm, such as 100 to 75,000 ppm, including 500 to 50,000 ppm, forexample 1000 to 25,000 ppm. As such, in some embodiments, the protonremoving agents present in the subterranean brines may comprise 5% ormore of borates, such about 10% or more of borates, including about 25%or more of borates, for instance about 50% or more of borates, such asabout 75% or more of borates, including about 90% or more of borates.Where both carbonate and borate are present, the molar ratio ofcarbonate to borate (i.e., carbonate:borate) in the subterranean brinesmay be between 1:1 and 1:2.5; 1:2.5 and 1:5; 1:5 and 1:10; 1:10 and1:25; 1:25 and 1:50; 1:50 and 1:100; 1:100 and 1:150; 1:150 and 1:200;1:200 and 1:250; 1:250 and 1:500; 1:500 and 1:1000, or a range thereof.For example, the molar ratio of carbonate to borate in subterraneanbrines of the invention may be between 1:1 and 1:10; 1:5 and 1:25; 1:10and 1:50; 1:25 and 1:100; 1:50 and 1:500; or 1:100 and 1:1000. In otherembodiments, the ratio of carbonate to borate (i.e., carbonate:borate)in the subterranean brine may be between 1:1 and 2.5:1; 2.5:1 and 5:1;5:1 and 10:1; 10:1 and 25:1; 25:1 and 50:1; 50:1 and 100:1; 100:1 and150:1; 150:1 and 200:1; 200:1 and 250:1; 250:1 and 500:1; 500:1 and1000:1, or a range thereof. For example, the ratio of carbonate toborate in the subterranean brines of the invention may be between 1:1and 10:1; 5:1 and 25:1; 10:1 and 50:1; 25:1 and 100:1; 50:1 and 500:1;or 100:1 and 1000:1.

In some embodiments, proton-removing agents present in subterraneanbrines may be an organic base. In some instances, the organic base maybe a monocarboxylic acid anion, e.g., formate, acetate, propionate,butyrate, and valerate, among others. In other instances, the organicbase may be a dicarboxylic acid anion, e.g., oxalate, malonate,succinate, and glutarate, among others. In other instances, the organicbase may be phenolic compounds, e.g., phenol, methylphenol, ethylphenol,and dimethylphenol, among others. In some embodiments, the organic basemay be a nitrogenous base, e.g., primary amines such as methyl amine,secondary amines such as diisopropylamine, tertiary amines such asdiisopropylethylamine, aromatic amines such as aniline, heteroaromaticssuch as pyridine, imidazole, and benzimidazole, and various formsthereof. The amount of organic base present in subterranean brines ofthe invention may vary. In some instances, the amount of organic basepresent in the brine ranges from 1 to 200 mmol/liter, such as 1 to 175mmol/liter, such as 1 to 100 mmol/liter, such as 10 to 100 mmol/liter,including 10 to 75 mmol/liter. Thus, in certain embodiments, protonremoving agents present in the subterranean brines may make up 5% ormore of organic base, such about 10% or more of organic base, includingabout 25% or more of organic base, for instance about 50% or more oforganic base, such as about 75% or more of organic base, including about90% or more of organic base.

In some embodiments, subterranean brines of the invention may have abacterial content. Examples of the types of bacteria that may be presentin subterranean brines include sulfur oxidizing bacteria (e.g.,Shewanella putrefaciens, Thiobacillus), aerobic halophilic bacteria(e.g., Salinivibrio costicola and Halomanos halodenitrificans), highsalinity bacteria (e.g., endospore-containing Bacillus and Marinococcushalophilus), among others. Bacteria may be present in subterraneanbrines of the invention in an amount that varies, such as where theconcentration is 1×10⁸ colony forming units/ml (cfu/ml) or less, such as5×10⁶ cfu/ml or less, such as 1×10⁵ cfu/ml or less, such as 5×10⁴ cfu/mlor less, such as 1×10³ cfu/ml or less, and including 1×10² cfu/ml orless. In some embodiments, the concentration of bacteria in thesubterranean brines may depend on the temperature of the brine. Forexample, at temperatures greater than about 80° C., subterranean brinesof the invention may have very little bacterial content, such as wherethe bacterial concentration is 1×10⁵ cfu/ml or less, such as 1×10⁴cfu/ml or less, such as 5×10³ cfu/ml or less, such as 1×10³ cfu/ml orless, such as 5×10² cfu/ml or less, including 1×10² cfu/ml or less.

In some embodiments, where subterranean brines have very littlebacterial content, substantially (e.g., 80% or more) the entirealkalinity (i.e., basicity) of the subterranean brine may be derivedfrom organic bases. In these embodiments, 80% or more, such as 90% ormore, including 95% or more, up to 100% of the alkalinity of thesubterranean brine may be derived from organic bases present in thesubterranean brine. At temperatures ranging between 20-80° C.,subterranean brines of the invention may have a high bacterial content.In these embodiments, the concentration of bacteria in the subterraneanbrine may be 1×10⁵ cfu/ml or greater, such as 5×10⁵ cfu/ml or greater,such as 1×10⁶ cfu/ml or greater, such as 5×10⁶ cfu/ml or greater, suchas 8×10⁶ cfu/ml or greater, including 1×10⁷ cfu/ml or greater. In someembodiments, where subterranean brines have a high bacterial content,very little of the alkalinity (e.g., 20% or less) of the subterraneanbrine may be derived from organic bases. In these embodiments, 20% orless, such as 15% or less, such as 10% or less, including 5% or less ofthe alkalinity of the subterranean brine may be derived from organicbases present in the subterranean brine.

Subterranean brines may be found at higher temperatures and pressuresthan other naturally occurring bodies of water such as oceans or lakes.The internal pressures brines in subterranean formations of theinvention may vary depending on the makeup of the brine as well as thedepth and geographic location of the subterranean formation, e.g.,ranging from 4-200 atm, such as 5 to 150 atm, such as 5 to 100 atm, suchas 5 to 50 atm, such as 5 to 25 atm, such as 5 to 15 atm, and including5 to 10 atm. In some embodiments, the subterranean brine is thermallyactive. The internal temperatures of subterranean brines of thisinvention may vary depending on the makeup of the composition as well asthe depth and geographic location of the subterranean formation, rangingfrom −5 to 250° C., such as 0 to 200° C., such as 5 to 150° C., such as10 to 100° C., such as 20 to 75° C., including 25 to 50° C. The elevatedtemperatures and pressures may be used to generate energy to drive oneor more process related to the sequestration of carbon dioxide.

In some embodiments, subterranean brines of the invention may havedistinct ranges or minimum or maximum levels of elements, ions, or othersubstances, for example, but not limited to: chloride, lithium, sodium,sulfur, fluoride, potassium, bromide, silicon, strontium, calcium,boron, magnesium, iron, barium and the like. In some embodiments,subterranean brines of the invention may include strontium, which may bepresent in the subterranean brine in an amount of up to 10,000 ppm orless, ranging in certain embodiments from 3 to 10,000 ppm, such as from5 to 5000 ppm, such as from 5 to 1000 ppm, e.g., 5 to 500 ppm, including5 to 100 ppm. In other embodiments, subterranean brines of the inventionmay include barium, which may be present in the subterranean brine in anamount of up to 2500 ppm or less, ranging in certain instances from 1 to2500 ppm, such as from 5 to 2500 ppm, such as from 10 to 1000 ppm, e.g.,10 to 500 ppm, including 10 to 100 ppm.

In other embodiments, subterranean brines of the invention may includeiron, which may be present in the subterranean brine in an amount of upto 5000 ppm or less, ranging in certain instances from 1 to 5000 ppm,such as from 5 to 5000 ppm, such as from 10 to 1000 ppm, e.g., 10 to 500ppm, including 10 to 100 ppm. In other embodiments, subterranean brinesof the invention may include sodium, which may be present in thesubterranean brine in an amount of up to 100,000 ppm or less, ranging incertain instances from 1000 to 100,000 ppm, such as from 1000 to 10,000ppm, such as from 1500 to 10,000 ppm, e.g., 2000 to 8000 ppm, including2000 to 7500 ppm. In other embodiments, subterranean brines of theinvention may include lithium, which may be present in the subterraneanbrine in an amount of up to 500 ppm or less, ranging in certaininstances from 0.1 to 500 ppm, such as from 1 to 500 ppm, such as from 5to 250 ppm, e.g., 10 to 100 ppm, including 10 to 50 ppm. In otherembodiments, subterranean brines of the invention may include chloride,which may be present in the subterranean brine in an amount of up to500,000 ppm or less, ranging in certain instances from 500 to 500,000ppm, such as from 1000 to 250,000 ppm, such as from 1000 to 100,000 ppm,e.g., 2000 to 100,000 ppm, including 2000 to 50,000 ppm. In otherembodiments, subterranean brines of the invention may include fluoride,which may be present in the subterranean brine in an amount of up to 100ppm or less, ranging in certain instances from 0.1 to 100 ppm, such asfrom 1 to 50 ppm, such as from 1 to 25 ppm, e.g., 2 to 25 ppm, including2 to 10 ppm. In other embodiments, subterranean brines of the inventionmay include potassium, which may be present in the subterranean brine inan amount of up to 100,000 ppm or less, ranging in certain instancesfrom 10 to 100,000 ppm, such as from 100 to 100,000 ppm, such as from1000 to 50,000 ppm, e.g., 1000 to 25,000 ppm, including 1000 to 10,000ppm.

In other embodiments, subterranean brines of the invention may includebromide, which may be present in the subterranean brine in an amount ofup to 5000 ppm or less, ranging in certain instances from 1 to 5000 ppm,such as from 5 to 5000 ppm, such as from 10 to 1000 ppm, e.g., 10 to 500ppm, including 10 to 100 ppm. In other embodiments, subterranean brinesof the invention may include silicon, which may be present in thesubterranean brine in an amount of up to 5000 ppm or less, ranging incertain instances from 1 to 5000 ppm, such as from 5 to 5000 ppm, suchas from 10 to 1000 ppm, e.g., 10 to 500 ppm, including 10 to 100 ppm. Inother embodiments, subterranean brines of the invention may includecalcium, which may be present in the subterranean brine in an amount ofup to 100,000 ppm or less, ranging in certain instances from 100 to100,000 ppm, such as from 100 to 50,000 ppm, such as from 200 to 10,000ppm, e.g., 200 to 5000 ppm, including 200 to 1000 ppm. In otherembodiments, subterranean brines of the invention may include boron,which may be present in the subterranean brine in an amount of up to1000 ppm or less, ranging in certain instances from 1 to 1000 ppm, suchas from 10 to 1000 ppm, such as from 20 to 500 ppm, e.g., 20 to 250 ppm,including 20 to 100 ppm. In other embodiments, subterranean brines ofthe invention may include magnesium, which may be present in thesubterranean brine in an amount of up to 10,000 ppm or less, ranging incertain instances from 10 to 10,000 ppm, such as from 50 to 5000 ppm,such as from 50 to 1000 ppm, e.g., 100 to 1000 ppm, including 100 to 500ppm.

In some embodiments, subterranean brines may be obtained from asubterranean location beneath or nearby a metal ore mine or petroleumfield and as such, may be rich in one or more identifiable traceelements (e.g., zinc, aluminum, lead, manganese, copper, cadmium,strontium, barium mercury, selenium, arsenic etc.) depending on the typeof metal ore mine or petroleum field and its vicinity to thesubterranean location where the subterranean brine is obtained. Thebrine may be used in mining activities before or after its use inmethods of this invention. The brine may be concentrated or otherwiseprocessed after mining activities prior to use in methods of thisinvention.

The concentration and identity of a trace element may provide anidentifiable physical profile of a particular brine. The trace elementor the above recited ions may be found in the calcium carbonateprecipitates prepared from such brines and as such may be used asmarkers for the calcium carbonate precipitates. In some embodiments, thetrace metal element in the subterranean brine is zinc, which may bepresent in the subterranean brine in an amount of up to 250 ppm or less,ranging in certain instances from 1 to 250 ppm, such as 5 to 250 ppm,such as from 10 to 100 ppm, e.g., 10 to 75 ppm, including 10 to 50 ppm.In other embodiments, the identifying trace metal element in thesubterranean brine is lead, which may be present in the subterraneanbrine in an amount of up to 100 ppm or less, ranging in certaininstances from 1 to 100 ppm, such as 5 to 100 ppm, such as from 10 to100 ppm, e.g., 10 to 75 ppm, including 10 to 50 ppm. In yet otherembodiments, the identifying trace metal element in the subterraneanbrine is manganese, which may be present in the subterranean brine in anamount of up to 200 ppm or less, ranging in certain instances from 1 to200 ppm, such as 5 to 200 ppm, such as from 10 to 200 ppm, e.g., 10 to150 ppm, including 10 to 100 ppm. In some embodiments, the subterraneanbrine may have a molar ratio of different carbonates which varies, e.g.,carbonates present in subterranean brines of the invention include, butare not limited to, carbonates of beryllium, magnesium, calcium,strontium, barium, radium or any combinations thereof.

In some embodiments, the subterranean brine may have an isotopiccomposition which varies depending on the factors which influenced itsformation and the location from which it is obtained. Many elements havestable isotopes, and these isotopes may be preferentially used invarious processes, e.g., biological processes and as a result, differentisotopes may be present in each subterranean brine in distinctiveamounts. An example is carbon, which will be used to illustrate oneexample of a subterranean brine described herein. However, it will beappreciated that these methods are also applicable to other elementswith stable isotopes if their ratios can be measured in a similarfashion to carbon; such elements may include nitrogen, sulfur, andboron. Methods for characterizing a composition by measuring itsrelative isotope composition (e.g., ^(δ13)C) is described in U.S. patentapplication Ser. No. 12/163,205, filed Jun. 27, 2008; the disclosure ofwhich is herein incorporated by reference. For example, the degree ofwater-rock exchange and the degree of mixing along fluid flow pathsbetween water and minerals can modify the isotopic composition of thesubterranean brine, in some instances the ratio of strontium-87 tostrontium-86 (⁸⁷Sr/⁸⁶Sr). In one embodiment, a brine may have a highinitial concentration of rubidium, such as brine found in granitesformations. One aspect of this invention is that brines may becharacterized by high strontium-87 to strontium-86 ratios. In someembodiments, the strontium-87:strontium-86 ratio of subterranean brinesof the invention may vary, ranging between 0.71/1 and 0.85/1, such asbetween 0.71/1 and 0.825/1, such as between 0.71/1 and 0.80/1, such asbetween 0.75/1 and 0.85/1, and including between 0.75/1 and 0.80/1. Anysuitable method may be used for measuring the strontium-87 tostrontium-86 ratio, methods including, but not limited to 90°-sectorthermal ionization mass spectrometry.

In some embodiments, subterranean brines of the invention may have acomposition which includes one or more identifying components whichdistinguish each subterranean brine from other subterranean brines. Assuch, the composition of each subterranean brine may be distinct fromone another. In some embodiments, subterranean brines may bedistinguished from one another by the amount and type of elements, ionsor other substances present in the subterranean brine (e.g., trace metalions, Hg, Se, As, etc). In other embodiments, subterranean brines may bedistinguished from one another by the molar ratio of carbonates presentin the subterranean brine. In other embodiments, subterranean brines maybe distinguished from one another by the amount and type of differentisotopes present in the subterranean brine (e.g., δ¹³C, δ¹⁸O, etc.). Inother embodiments, subterranean brines may be distinguished from oneanother by the isotopic ratio of particular elements present in thesubterranean brine (e.g., ⁸⁷Sr/⁸⁶Sr).

Methods

A variety of different methods may be employed to prepare the CO₂sequestering calcium carbonates of the compositions of the invention.CO₂ sequestration protocols of interest include, but are not limited to,those disclosed in U.S. patent application Ser. No. 12/126,776, titled,“Hydraulic cements including carbonate compound compositions,” filed 23May 2008; Ser. No. 12/163,205, titled “DESALINATION METHODS AND SYSTEMSTHAT INCLUDE CARBONATE COMPOUND PRECIPITATION,” filed 27 Jun. 2008; andSer. No. 12/486,692, titled “METHODS AND SYSTEMS FOR UTILIZING WASTESOURCES OF METAL OXIDES” filed 17 Jun. 2009; U.S. patent applicationSer. No. 12/501,217, titled “PRODUCTION OF CARBONATE-CONTAININGCOMPOSITIONS FROM MATERIAL COMPRISING METAL SILICATE,” filed 10 Jul.2009; and U.S. patent application Ser No. 12/557,492, titled “CO₂COMMODITY TRADING SYSTEM AND METHOD,” filed 10 Sep. 2009; as well asInternational Application No. PCT/US08/88318, titled, “METHODS OFSEQUESTERING CO₂,” filed 24 Dec. 2008; and PCT/US09/45722, titled “ROCKAND AGGREGATE, AND METHODS OF MAKING AND USING THE SAME,” filed 29 May2009; as well as pending U.S. Provisional Patent Application Ser. Nos.61/081,299; 61/082,766; 61/088,347; 61/088,340; and 61/101,631; thedisclosures of which are herein incorporated by reference in theirentireties.

FIG. 1 provides an illustrative schematic flow diagram of a carbonateprecipitation process according to some embodiments of the invention. InFIG. 1, any source of water, such as, for example only, saltwater fromsalt water source containing alkaline earth metal ions or an alkalineearth metal ion containing water 10 is subjected to one or moreconditions at precipitation step 20. In some embodiments depicted inFIG. 1, the water from saltwater source or an alkaline earth-metalcontaining water 10 is first contacted with source of CO₂ 30 which maybe a CO₂ gaseous stream to make CO₂ charged water. By CO₂ charged wateris meant water that has had CO₂ gas contacted with it and/or where CO₂molecules have combined with water molecules to produce, e.g., carbonicacid, bicarbonate and carbonate ion. Charging water in this step resultsin an increase in the CO₂ content of the water, e.g., in the form ofcarbonic acid, bicarbonate and carbonate ion, and a concomitant decreasein the pCO₂ of the waste stream that is contacted with the water. TheCO₂ charged water may be acidic, having a pH of 6 or less, such as 5 orless and including 4 or less. In certain embodiments, the concentrationof CO₂ of the gas that is used to charge the water is 10% or higher, 25%or higher, including 50% or higher, such as 75% or even higher.

In some embodiments, the water from saltwater source or the alkalineearth-metal containing water 10 is first contacted with a solutioncharged with the partially or fully dissolved CO₂, which CO₂ is thensubjected to one or more carbonate compound precipitation conditions. Asdepicted in FIG. 1, the source of CO₂ 30 includes a gaseous stream orthe solution containing the CO₂ which is contacted with the water atprecipitation step 20.

In some embodiments, the solution charged with the partially or fullydissolved CO₂ is made by parging or diffusing the CO₂ gaseous streamthrough a solution to make a CO₂ charged water. In some embodiments, thesolution with CO₂ includes a proton removing agent. In some embodiments,the CO₂ gas is bubbled or parged through a solution containing a protonremoving agent, such as sodium or potassium hydroxide, in an absorber.In some embodiments, the absorber may include a bubble chamber where theCO₂ gas is bubbled through the solution containing the proton removingagent. In some embodiments, the absorber may include a spray tower wherethe solution containing the proton removing agent is sprayed orcirculated through the CO₂ gas. In some embodiments, the absorber mayinclude a pack bed to increase the surface area of contact between theCO₂ gas and the solution containing the proton removing agent. In someembodiments, a typical absorber fluid temperature is 32-37° C. Theabsorber for absorbing CO₂ in the solution is described in U.S.application Ser. No. 12/721,549, filed on Mar. 10, 2010, which isincorporated herein by reference in its entirety.

In some embodiments, an order for the addition of the source of CO₂ andthe alkaline earth metal containing water to the reactor for theprecipitation, may be varied. In some embodiments, the CO₂ gaseousstream or the solution containing the partially or fully dissolved CO₂or the affluent from the absorber containing an alkaline solution of CO₂is added to the reactor containing the alkaline earth-metal containingwater for precipitation of the carbonate precipitate in theprecipitation step 20. In some embodiments, the alkaline earth-metalcontaining water is added to the reactor containing the CO₂ gaseousstream or the solution containing the partially or fully dissolved CO₂or the affluent from the absorber containing an alkaline solution of CO₂for precipitation of the carbonate precipitate in the precipitation step20. In some embodiments, the alkaline earth-metal containing water isadded to the reactor containing less than 20%, or less than 15%, or lessthan 10%, or less than 5% of the CO₂ gaseous stream or the solutioncontaining the partially or fully dissolved CO₂ or the affluent from theabsorber containing an alkaline solution of CO₂ for precipitation of thecarbonate precipitate in the precipitation step 20.

Contact protocols include, but are not limited to, direct contactingprotocols, e.g., bubbling the gas through the volume of water;concurrent contacting means, e.g., contact between unidirectionallyflowing gaseous and liquid phase streams; and countercurrent means,e.g., contact between oppositely flowing gaseous and liquid phasestreams, and the like. Thus, contact may be accomplished through use ofinfusers, bubblers, fluidic Venturi reactor, sparger, gas filter, spray,tray, or packed column reactors, and the like, as may be convenient. Insome embodiments, the contact is by spray. In some embodiments, thecontact is through packed column.

In some embodiments, the methods include contacting the volume of waterthat is subjected to the mineral precipitation conditions with a sourceof CO₂. The contacting of the water with the source of CO₂ may occurbefore and/or during the time when the water is subject to CO₂ in one ormore conditions or one or more precipitation conditions. Accordingly,embodiments of the invention include methods in which the volume ofwater is contacted with a source of CO₂ prior to subjecting the volumeof saltwater to mineral precipitation conditions. Embodiments of theinvention include methods in which the volume of salt water is contactedwith a source of CO₂ while the volume of saltwater is being subjected tomineral precipitation conditions. Embodiments of the invention includemethods in which the volume of water is contacted with a source of a CO₂both prior to subjecting the volume of water to mineral precipitationconditions and while the volume of water is being subjected to carbonatecompound precipitation conditions. In some embodiments, the same watermay be cycled more than once, wherein a first cycle of precipitationremoves primarily calcium carbonate and magnesium carbonate minerals,and leaves remaining alkaline water to which other alkaline earth ionsources may be added, that can have more carbon dioxide cycled throughit, precipitating more carbonate compounds.

The CO₂ charging and carbonate compound precipitation may occur in acontinuous process or at separate steps. As such, charging andprecipitation may occur in the same reactor of a system, e.g., asillustrated in FIG. 1 at step 20, according to some embodiments of theinvention. In yet other embodiments of the invention, these two stepsmay occur in separate reactors, such that the water is first chargedwith CO₂ in a charging reactor and the resultant CO₂ charged water isthen subjected to precipitation conditions in a separate reactor.

In methods of making the composition of the invention, a volume of wateris subjected to one or more conditions or precipitation conditionssufficient to produce a precipitated carbonate compound composition andmother liquor (i.e., the part of the water that is left over afterprecipitation of the carbonate compound(s) from water). At precipitationstep 20, carbonate compounds, which may be amorphous or crystalline, areprecipitated. This precipitate may be the self-cementing compositionproduct 80 and may be stored as is or may be further processed to makethe cement products. Alternatively, the precipitate may be subjected tofurther processing to give the hydraulic cement or the SCM compositionsof the invention.

The one or more conditions or one or more precipitation conditions ofinterest include those that change the physical environment of the waterto produce the desired precipitate product. The one or more conditionsor precipitation conditions include, but are not limited to, one or moreof temperature, pH, precipitation, residence time of the precipitate,dewatering or separation of the precipitate, drying, milling, andstorage. For example, the temperature of the water may be within asuitable range for the precipitation of the desired composition tooccur. For example, the temperature of the water may be raised to anamount suitable for precipitation of the desired carbonate compound(s)to occur. In such embodiments, the temperature of the water may be from5 to 70° C., such as from 20 to 50° C., and including from 25 to 45° C.As such, while a given set of precipitation conditions may have atemperature ranging from 0 to 100° C., the temperature may be raised incertain embodiments to produce the desired precipitate. In certainembodiments, the temperature is raised using energy generated from lowor zero carbon dioxide emission sources, e.g., solar energy source, windenergy source, hydroelectric energy source, etc.

The residence time of the precipitate in the reactor before theprecipitate is removed from the solution, may vary. In some embodiments,the residence time of the precipitate in the solution is more than 5seconds, or between 5 seconds-1 hour, or between 5 seconds-1 minute, orbetween 5 seconds to 20 seconds, or between 5 seconds to 30 seconds, orbetween 5 seconds to 40 seconds. Without being limited by any theory, itis contemplated that the residence time of the precipitate may affectthe size of the particle. For example, a shorter residence time may givesmaller size particles or more disperse particles whereas longerresidence time may give agglomerated or larger size particles. In someembodiments, the residence time in the process of the invention may beused to make small size as well as large size particles in a single ormultiple batches which may be separated or may remain mixed for latersteps of the process. In some embodiments, the finely disperse particlesmay be processed further to give the SCM composition of the invention.In some embodiments, the large or agglomerated particles may beprocessed to give the hydraulic cement composition and/or theself-cementing composition of the invention.

While the pH of the water may range from 7 to 14 during a givenprecipitation process, in certain embodiments the pH is raised toalkaline levels in order to drive the precipitation of carbonatecompound as desired. In some embodiments, the pH is raised to a levelwhich minimizes if not eliminates CO₂ gas generation production duringprecipitation. In these embodiments, the pH may be raised to 10 orhigher, such as 11 or higher. In some embodiments, the one or moreconditions or the precipitation conditions include contacting thesaltwater or the alkaline-earth metal containing water with a protonremoving agent. The proton removing agent may be any proton removingagent, as described herein, for example, but not limited to, oxide,hydroxide, such as sodium hydroxide, carbonate, coal ash, naturallyoccurring mineral, and combination thereof. In some embodiments, the oneor more conditions or the precipitation conditions include contactingthe saltwater or the alkaline-earth metal containing water toelectrochemical conditions. Such electrochemical conditions have beendescribed herein. The nature of the precipitate may be affected by thepH of the precipitation process. In some embodiments, high pH may leadto rapid precipitation and agglomeration of the particles whereas lowerpH or slow raise in the pH may lead to finer particles.

The nature of the precipitate may also be influenced by selection ofappropriate major ion ratios. Major ion ratios may have influence onpolymorph formation. For example, magnesium may stabilize the vateriteand/or amorphous calcium carbonate in the precipitate.

Rate of precipitation may also influence compound polymorphic phaseformation and may be controlled in a manner sufficient to produce adesired precipitate product. The most rapid precipitation can beachieved by seeding the solution with a desired phase. Without seeding,rapid precipitation can be achieved by rapidly increasing the pH of thesea water. The higher the pH is, the more rapid the precipitation maybe.

In some embodiments, a set of conditions to produce the desiredprecipitate from the water include, but are not limited to, the water'stemperature and pH, and in some instances the concentrations ofadditives and ionic species in the water. Precipitation conditions mayalso include factors such as mixing rate, forms of agitation such asultrasonics, and the presence of seed crystals, catalysts, membranes, orsubstrates. In some embodiments, precipitation conditions includesupersaturated conditions, temperature, pH, and/or concentrationgradients, or cycling or changing any of these parameters. The protocolsemployed to prepare carbonate compound precipitates according to theinvention may be batch or continuous protocols. It will be appreciatedthat precipitation conditions may be different to produce a givenprecipitate in a continuous flow system compared to a batch system. Theone or more of the precipitation conditions, as described herein, may bemodulated to obtain a precipitate with a desired particle size,reactivity, and zeta potential. This may further affect the compressivestrength of the cement formed when the composition is combined withfresh water, set and hardenend.

Following production of the carbonate compound precipitate from thewater, the resultant precipitated carbonate compound composition may beseparated from the mother liquor or dewatered to produce the precipitateproduct, as illustrated at step 40 of FIG. 1. Alternatively, theprecipitate is left as is in the mother liquor or mother suprenate.

Separation of the precipitate can be achieved using any convenientapproach, including a mechanical approach, e.g., where bulk excess wateris drained from the precipitated, e.g., either by gravity alone or withthe addition of vacuum, mechanical pressing, by filtering theprecipitate from the mother liquor to produce a filtrate, or usingcentrifugation techniques, etc. Separation of bulk water produces a wet,dewatered precipitate.

The above protocol results in the production of slurry of a CO₂sequestering precipitate and mother liquor. This precipitate in themother liquor and/or in the slurry may give the self-cementingcomposition of the invention. In some embodiments, a portion or whole ofthe dewatered precipitate or the slurry is further prcessed to make thehydraulic cement or the SCM compositions of the invention.

Where desired, the compositions made up of the precipitate and themother liquor may be stored for a period of time following precipitationand prior to further processing. For example, the composition may bestored for a period of time ranging from 1 to 1000 days or longer, suchas 1 to 10 days or longer, at a temperature ranging from 1 to 40° C.,such as 20 to 25° C.

The slurry components are then separated. Embodiments may includetreatment of the mother liquor, where the mother liquor may or may notbe present in the same composition as the product. For example, wherethe mother liquor is to be returned to the ocean, the mother liquor maybe contacted with a gaseous source of CO₂ in a manner sufficient toincrease the concentration of carbonate ion present in the motherliquor. Contact may be conducted using any convenient protocol, such asthose described above. In certain embodiments, the mother liquor has analkaline pH, and contact with the CO₂ source is carried out in a mannersufficient to reduce the pH to a range between 5 and 9, e.g., 6 and 8.5,including 7.5 to 8.2. In certain embodiments, the treated brine may becontacted with a source of CO₂, e.g., as described above, to sequesterfurther CO₂.

The resultant mother liquor of the reaction may be disposed of using anyconvenient protocol. In certain embodiments, it may be sent to atailings pond for disposal. In certain embodiments, it may be disposedof in a naturally occurring body of water, e.g., ocean, sea, lake orriver. In certain embodiments, the mother liquor is returned to thesource of feedwater for the methods of invention, e.g., an ocean or sea.Alternatively, the mother liquor may be further processed, e.g.,subjected to desalination protocols, as described further in U.S.application Ser. No. 12/163,205, filed Jun. 27, 2008; the disclosure ofwhich is herein incorporated by reference.

The resultant dewatered precipitate is then dried to produce thecomposition of the invention, as illustrated at step 60 of FIG. 1.Drying can be achieved by air drying, spray drying, vacuum drying,and/or oven drying the precipitate. Where the precipitate is air dried,air drying may be at a temperature ranging from −70 to 120° C., asdesired. In certain embodiments, drying is achieved by freeze-drying(i.e., lyophilization), where the precipitate is frozen, the surroundingpressure is reduced and enough heat is added to allow the frozen waterin the material to sublime directly from the frozen precipitate phase togas. In yet another embodiment, the precipitate is spray dried to drythe precipitate, where the liquid containing the precipitate is dried byfeeding it through a hot gas (such as the gaseous waste stream from thepower plant), e.g., where the liquid feed is pumped through an atomizerinto a main drying chamber and a hot gas is passed as a co-current orcounter-current to the atomizer direction. Depending on the particulardrying protocol of the system, the drying station may include afiltration element, freeze drying structure, spray drying structure,etc. The drying of the precipitate may include temperature between150-180° C. or between 150-250° C., or between 150-200° C.

In some embodiments, the step of spray drying may include separation ofdifferent sized particles of the precipitate. For example, a first batchof larger sized particles may be collected from the spray dryer followedby the collection of the smaller sized particles. In some embodiments, asingle batch may give one or more, such as, for example only, two,three, four, or five different sizes of the particles (e.g., micron andsub-micron particles as defined herein) which may be separated for lateruse or which different sized particle may be mixed together to make thecomposition of the invention.

In some embodiments, the particles with different morphologies, such asfine or agglomerated, and/or the particles with different sizes may bemixed to make the compositions of the invention. For example, acomposition of the invention may include a mix of fine disperseparticles with larger agglomerated particles or the composition of theinvention may include a mix of particles with different sizes, e.g.,particles with sizes ranging between 0.1 micron to 100 micron. In someembodiments, the composition of the invention may be modulated by mixingthe particles with different particle size, surface area, zetapotential, and/or morphologies.

Where desired, the dewatered precipitate product from the separationreactor 40 may be washed before drying, as illustrated at step 50 ofFIG. 1. The precipitate may be washed with freshwater, e.g., to removesalts (such as NaCl) from the dewatered precipitate. The water used forwashing may contain metals, such as, iron, nickel, etc. In someembodiments, the precipitate may be rinsed with fresh water to removehalite or the chloride content from the precipitate. The chloride may beundesirable in some applications, for example, in aggregates intendedfor use in concrete since the chloride has a tendency to corrode rebar.Further, the rinsing of the slurry or the precipitate with water maycause the vaterite in the composition to shift to more stable forms suchas aragonite and calcite and result in the cemented material. In someembodiments, such rinsing may not be desirable as it may reduce theyield of the composition. In such embodiments, the precipitate may bewashed with a solution having a low chloride concentration but highconcentration of divalent cations (such as, calcium, magnesium, etc.).Such high concentration of the divalent ion may prevent the dissolutionof the precipitate, thereby reducing the yield loss and the conversionto cemented material. In some embodiments, the precipitate may be washedor rinsed with water containing stabilizing additives, such as sodiumstearate. The stabilizing additives may act as ligands that may alterthe surface charge of the precipitate, thereby stabilizing it. Thestabilization of the precipitate may prevent the dissolution of theprecipitate, thereby reducing the yield loss and the conversion tocemented material. Used wash water may be disposed of as convenient,e.g., by disposing of it in a tailings pond, etc.

At step 70, the dried precipitate is refined, milled, aged, and/orcured, e.g., to provide for desired physical characteristics, such asparticle size, surface area, zeta potential, etc., or to add one or morecomponents to the precipitate, such as admixtures, aggregate,supplementary cementitious materials, etc., to produce a finalcomposition of the invention 80. Refinement may include a variety ofdifferent protocols. In certain embodiments, the product is subjected tomechanical refinement, e.g., grinding, in order to obtain a product withdesired physical properties, e.g., particle size, etc. The driedprecipitate may be milled or ground to obtain a desired particle size.

Aspects of the invention further include systems, e.g., processingplants or factories, for producing the carbonate compound compositions,e.g., saltwater derived carbonate and hydroxide mineral compositions,and cements of the invention, as well as concretes and mortars thatinclude the cements of the invention. Systems of the invention may haveany configuration which enables practice of the particular productionmethod of interest.

In one aspect, there is provided a system for making the composition ofthe invention, including (a) an input for an alkaline earth-metalcontaining water; (b) an input for a flue gas from an industrial plantincluding carbon of a fossil fuel origin; and (c) a reactor connected tothe inputs of step (a) and step (b) that is configured to make thecomposition of the invention. In another aspect, there is provided asystem for making a composition, including (a) an input for an alkalineearth-metal containing water; (b) an input for a CO₂ source; and (c) areactor connected to the inputs of step (a) and step (b) that isconfigured to make a composition, wherein the composition comprises atleast 47% w/w vaterite and wherein the composition upon combination withwater, setting, and hardening has a compressive strength of at least 14MPa.

FIG. 2 provides an illustrative schematic of a system to conduct themethods of some embodiments of the invention. In FIG. 2, system 100includes water source 110, such as, alkaline earth-metal containingwater. In some embodiments, water source 110 includes a structure havingan input for salt water, such as a pipe or conduit from an ocean, etc.Where the salt water source is seawater, the input is in fluidcommunication with a source of sea water. For example, the input is apipe line or feed from ocean water to a land based system or an inletport in the hull of ship, e.g., where the system is part of a ship,e.g., in an ocean based system. Water may be removed and sent to thesystems of the invention by any convenient protocol, such as, but notlimited to, turbine motor pump, rotary lobe pump, hydraulic pump, fluidtransfer pump, geothermal well pump, a water-submersible vacuum pump,among other protocols.

The methods and systems of the invention may also include one or moredetectors configured for monitoring the source of water or the source ofcarbon dioxide (not illustrated in FIG. 1 or FIG. 2). Monitoring mayinclude, but is not limited to, collecting data about the pressure,temperature and composition of the water or the carbon dioxide gas. Thedetectors may be any convenient device configured to monitor, forexample, pressure sensors (e.g., electromagnetic pressure sensors,potentiometric pressure sensors, etc.), temperature sensors (resistancetemperature detectors, thermocouples, gas thermometers, thermistors,pyrometers, infrared radiation sensors, etc.), volume sensors (e.g.,geophysical diffraction tomography, X-ray tomography, hydroacousticsurveyers, etc.), and devices for determining chemical makeup of thewater or the carbon dioxide gas (e.g, IR spectrometer, NMR spectrometer,UV-vis spectrophotometer, high performance liquid chromatographs,inductively coupled plasma emission spectrometers, inductively coupledplasma mass spectrometers, ion chromatographs, X-ray diffractometers,gas chromatographs, gas chromatography-mass spectrometers,flow-injection analysis, scintillation counters, acidimetric titration,and flame emission spectrometers, etc.).

In some embodiments, detectors for monitoring the subterranean carbonatebrine may also include a computer interface which is configured toprovide a user with the collected data about the water or the carbondioxide gas. For example, a detector may determine the internal pressureof the water or the carbon dioxide gas and the computer interface mayprovide a summary of the changes in the internal pressure within the thewater or the carbon dioxide gas over time. In some embodiments, thesummary may be stored as a computer readable data file or may be printedout as a user readable document.

In some embodiments, the detector may be a monitoring device such thatit can collect real-time data (e.g., internal pressure, temperature,etc.) about the the water or the carbon dioxide gas. In otherembodiments, the detector may be one or more detectors configured todetermine the parameters of the water or the carbon dioxide gas atregular intervals, e.g., determining the composition every 1 minute,every 5 minutes, every 10 minutes, every 30 minutes, every 60 minutes,every 100 minutes, every 200 minutes, every 500 minutes, or some otherinterval.

FIG. 2 also shows a CO₂ source 130. This source may vary, as describedabove. In some embodiments, the CO₂ source 130 includes a structurehaving an input for CO₂, such as a pipe or conduit. Where the CO₂ sourceis flue gas from the power plant, the input is in gaseous communicationwith the source of CO₂ in the plant. For example, the input is a pipeline or feed from power plant to the system. Alternatively, the CO₂source may be a cylinder or series of cylinders connected to the inputfor the CO₂ source. In some embodiments, the CO₂ source is a solutioncontaining CO₂, as described above.

The inputs for the water source and the CO₂ source are connected to theCO₂ charger and precipitator reactor 120. The precipitation reactor 120is connected to the two inputs and is configured to make the carbonateprecipitate. The charger and precipitation reactor 120 may be configuredto include any number of different elements, such as temperatureregulators (e.g., configured to heat the water to a desiredtemperature), chemical additive elements, e.g., for introducing chemicalpH elevating agents (such as NaOH) into the water, electrolysiselements, e.g., cathodes/anodes, etc. This reactor 120 may operate as abatch process or a continuous process. It is to be understood thatsystem in FIG. 2 is for illustration purposes only and that the systemmay be modified to achieve the same result. For example, the system mayhave more than one reactor, and/or more than one source of alkalineearth metal ions, and/or more than one source of CO₂ interconnected inthe system. The charger and/or reactor can be a continuous stir tankreactor (CSTR), plug flow reactor (PFR), a tank, a batch reactor, orcombination thereof. Such reactors, such as, CSTR, PFR, etc. are wellknown in the art. In some embodiments, the reactor is PFR. The PFR mayhave pipes optionally with inline mixing elements to mix the solutions.In some embodiments, the turbulence in the pipe mixes the solutionswithout the need for mixing elements. In some embodiments, static inlinemixing elements may be present inside the pipes to mix the solutions.The length and the diameter of the pipes may be modulated that mayaffect the mixing of the solutions, the residence time of theprecipitate, the morphology of the precipitate, the particle size of theprecipitate, etc. In some embodiments, the inside of the pipes in thePFR may be coated with a material that resists the build up of theprecipitate inside the pipes. Such coating can be Teflon or any othermaterial. An average flow of the solution containing the partially orfully dissolved CO₂ or the affluent from the absorber containing analkaline solution of CO₂ to the reactor may be 4-6 GPM (gallons perminute), or 5-6 GPM, or 4-5 GPM, or 3-8 GPM. An average flow of thealkaline earth metal ion containing water to the reactor may be 8-10 GPM(gallons per minute), or 8-9 GPM, or 9-10 GPM, or 5-15 GPM.

The product of the precipitation reaction, e.g., the slurry may beremoved from the reactor and used to make the self-cementing compositionof the invention. Alternatively, the product of the precipitationreaction, e.g., the slurry is then processed at a bulk dewateringstation 140, as illustrated in FIG. 2. The dewatering station 140 mayuse a variety of different water removal processes, including processessuch as continuous centrifugation, centrifugation, filtercentrifugation, gravitational settling, and the like. The slurryobtained after bulk dewatering but still wetted in a mother supernatecan be used to make the self-cementing composition of the invention. Thedewatering station 140 may be any number of dewatering stationsconnected to each other to dewater the slurry (e.g., parallel, inseries, or combination thereof).

In some embodiments, systems may also include a desalination station(not illustrated in FIG. 2). The desalination station may be in fluidcommunication with the liquid-solid separator 140 such that the liquidproduct may be conveyed from the liquid-solid separator to thedesalination station directly. The systems may include a conveyance(e.g., pipe) where the output depleted brine may be directly pumped intothe desalination station or may flow to desalination station by gravity.Desalination stations of the invention may employ any convenientprotocol for desalination, and may include, but are not limited todistillers, vapor compressors, filtration devices, electrodialyzers,ion-exchange membranes, nano-filtration membranes, reverse osmosisdesalination membranes, multiple effect evaporators or a combinationthereof.

The system shown in FIG. 2 may also include a drying station 160 or aseries of drying stations for drying the dewatered precipitate producedat station 140. Depending on the particular drying protocol of thesystem, the drying station 160 may include a filtration element, freezedrying structure, oven drying, spray drying structure, etc., asdescribed above.

Also shown in FIG. 2, is an optional washing station 150, where bulkdewatered precipitate from separation station 140 is washed, e.g., toremove salts and other solutes from the precipitate, prior to drying atthe drying station 160. Dried precipitate from station 160 is then sentto refining station 170, where the precipitate may be mechanicallyprocessed and/or one or more components may be added to the precipitate(e.g., as described above) to produce the hydraulic cement and SCMcompositions of the invention. The refining station 170 may havegrinders, millers, crushers, compressors, blender, etc. in order toobtain desired physical properties in the composition of the invention.

The system may further include outlet conveyers, e.g., conveyer belt,slurry pump, that allow for the removal of precipitate from one or moreof the following: the contacting reactor, precipitation reactor, dryingstation, or from the refining station. In certain embodiments, thesystem may further include a station for preparing a building material,such as cement, from the precipitate. This station can be configured toproduce a variety of cements, aggregates, or cementitious materials fromthe precipitate, such as described herein.

In some embodiments, the system of the invention includes a processingstation that may include a compressor configured to pressurize the fluegas or the source of carbon dioxide, the source of alkaline earth metalions, the reaction mixture in the reactor, the precipitate, thedewatered precipitate and/or the dried precipitate, as desired.Compressors of the invention may employ any convenient compressionprotocol, and may include, but are not limited to, positive displacementpumps (e.g., piston or gear pumps), static or dynamic fluid compressionpumps, radial flow centrifugal-type compressors, helical blade-typecompressors, rotary compressors, reciprocating compressors, liquid-ringcompressors, among other devices for fluid compression. In someembodiments, the compressor may be configured to pressurize to apressure of 5 atm or greater, such as 10 atm or greater, such as 25 atmor greater, including 50 atm or greater.

In some embodiments, the systems of the invention may include a controlstation, configured to control the amount of the carbon dioxide and/orthe amount of alkaline earth metal ions conveyed to the precipitator orthe charger; the amount of the precipitate conveyed to the separator;the amount of the precipitate conveyed to the drying station; and/or theamount of the precipitate conveyed to the refining station. A controlstation may include a set of valves or multi-valve systems which aremanually, mechanically or digitally controlled, or may employ any otherconvenient flow regulator protocol. In some instances, the controlstation may include a computer interface, (where regulation iscomputer-assisted or is entirely controlled by computer) configured toprovide a user with input and output parameters to control the amount,as described above.

As indicated above, the system may be present on land or sea. Forexample, the system may be a land based system that is in a coastalregion, e.g., close to a source of sea water, or even an interiorlocation, where water is piped into the system from a salt water source,e.g., ocean. Alternatively, the system may be a water based system,e.g., a system that is present on or in water. Such a system may bepresent on a boat, ocean based platform etc., as desired.

It is to be understood that the methods and the systems depicted in thefigures are in no way limiting to the scope of the invention. One ormore the steps in the methods may be skipped or the order of the stepsmay be altered to make the products and compositions of the invention.Similarly, one or more of the components in the systems may be avoidedto make the products and compositions of the invention. For example, thesource of cation may already be present in the reactor when the CO₂source is added to the reactor, or vice versa.

III. Methods and Systems of Use

Aspects of the invention also provide methods and systems for making acement product from the compositions of the invention. The compositionsof the invention may be used to make cement products such as buildingmaterials or pre-cast or formed building materials, and/or aggregates.

In one aspect, there is provided a method for making a cement productfrom the composition of the invention, including (a) combining thecomposition of the invention with an aqueous medium under one or moresuitable conditions; and (b) allowing the composition to set and hardeninto a cement product. In some embodiments, the methods compriseaddition of Portland cement clinker, aggregate, SCM, or a combinationthereof to the composition, before combining the composition with theaqueous medium.

In one aspect, there is provided a method for making formed buildingmaterial from the compositions of the invention, such as, the hydrauliccement composition, the SCM composition, or the self-cementingcomposition, by combining the composition with an aqueous medium underone or more suitable conditions; and allowing the composition to set andharden into the formed building material. In some embodiments, thecomposition is poured into molds before or after step (a) of thecombination. In some embodiments, the mold is for the formed buildingmaterial. In some embodiments, the aqueous medium includes fresh water.

In some embodiments the invention provides a method of producing acement product including the composition of the invention by obtainingthe composition of the invention; and producing a cement product. Insome embodiments the obtaining step comprises precipitating thecomposition from a divalent cation-containing water, e.g., analkaline-earth-metal-ion containing water such as salt water, e.g., seawater. The obtaining step may further comprise contacting the divalentcation-containing water, e.g., alkaline-earth-metal-ion containingwater, to an industrial gaseous waste stream including CO₂ prior to,and/or during, the precipitating step. The industrial gaseous wastestream may be any stream as described herein, such as from a powerplant, foundry, cement plant, refinery, or smelter, e.g. a flue gas. Insome embodiments the obtaining step further comprises raising the pH ofthe alkaline-earth-metal-ion containing water to 10 or higher prior toor during the precipitating step. The producing step may includeallowing the composition to form a solid product, such as by mixing thecomposition with an aqueous medium including, but not limited to, one ormore of fresh water, Portland cement, fly ash, lime and a binder, andoptionally mechanically refining the solid product, such as by molding,extruding, pelletizing or crushing. The producing step may includecontacting the composition with fresh water to convert the polymorphs inthe composition to a freshwater stable product. In some embodiments,this may be done by spreading the composition in an open area; andcontacting the spread composition with fresh water.

In some embodiments, the aggregate producer comprises a refining stationto mechanically refine the aggregate made from the composition of theinvention.

In some embodiments, the composition of the invention after mixing inthe water is poured into the molds designed to make one or more of thepre-formed building material. The composition is then allowed to set andharden into the pre-formed or pre-cast material.

Upon precipitation of calcium carbonate as described herein, amorphouscalcium carbonate (ACC) may initially precipitate and transform into oneor more of its three more stable phases (vaterite, aragonite, orcalcite). A thermodynamic driving force may exist for the transformationfrom unstable phases to more stable phases, as described by Ostwald inhis Step Rule (Ostwald, W. Zeitschrift fur Physikalische Chemie 289(1897)). For this reason, calcium carbonate phases transform in theorder: ACC to vaterite, aragonite, and calcite where intermediate phasesmay or may not be present. For instance, ACC can transform to vateriteand may not transform to aragonite or calcite; or ACC can transform tovaterite and then directly to calcite, skipping the aragonite form; oralternatively, ACC can transform to vaterite and then to aragonitewithout transforming to calcite. During this transformation, excesses ofenergy are released, as exhibited by FIG. 3. This intrinsic energy maybe harnessed to create a strong aggregation tendency and surfaceinteractions that may lead to agglomeration and cementing. It is to beunderstood that the values reported in FIG. 3 are well known in the artand may vary.

The transformation between calcium carbonate polymorphs may occur viasolid-state transition or may be solution mediated. In some embodiments,the transformation is solution-mediated because it may require lessenergy than the thermally activated solid-state transition. Thesolution-mediated transformation is environmentally conscious and moreapplicable to a cementing application. Vaterite is metastable and thedifference in thermodynamic stability of calcium carbonate polymorphsmay be manifested as a difference in solubility, where the least stablephases are the most soluble (Ostwald, supra.). Therefore, vaterite maydissolve readily in solution and transform favorably towards a morestable polymorph: aragonite or calcite. The driving force for theformation of a particular calcium carbonate polymorph or combination ofpolymorphs is the change in Gibbs free energy from a supersaturatedsolution to equilibrium (Spanos & Koutsoukos Journal of Crystal Growth(1998) 191, 783-790).

In a polymorphic system like calcium carbonate, two kinetic processesmay exist simultaneously in solution: dissolution of the metastablephase and growth of the stable phase (Kralj et al. Journal of CrystalGrowth (1997) 177, 248-257). In some embodiments, the aragonite orcalcite crystals may be growing while vaterite is undergoing dissolutionin the aqueous medium.

Crystallization of the polymorphs is a surface controlled process whereheterogeneous nucleation may be responsible for the formation ofmultiple solid phases. When a single phase is present, the number ofparticles may decrease with time, while their size increases (Spanos &Koutsoukos, supra.). Vaterite may be framboidal (spherical aggregates ofdiscrete micro/nano-crystallites) or non-framboidal.

In some embodiments, the composition of the invention, as prepared bythe methods described above, is treated with the aqueous medium underone or more suitable conditions. The aqueous medium includes, but is notlimited to, fresh water optionally containing sodium chloride, calciumchloride, magnesium chloride, or combination thereof or aqueous mediummay be brine. In some embodiments, aqueous medium is fresh water.

In some embodiments, the one or more suitable conditions include, butare not limited to, temperature, pressure, time period for setting, aratio of the aqueous medium to the composition, and combination thereof.The temperature may be related to the temperature of the aqueous medium.In some embodiments, the temperature is in a range of 0-110° C.; or0-80° C.; or 0-60° C.; or 0-40° C.; or 25-100° C.; or 25-75° C.; or25-50° C.; or 37-100° C.; or 37-60° C.; or 40-100° C.; or 40-60° C.; or50-100° C.; or 50-80° C.; or 60-100° C.; or 60-80° C.; or 80-100° C. Insome embodiments, the pressure is atmospheric pressure or above atm.pressure. In some embodiments, the time period for setting the cementproduct is 30 min. to 48 hrs; or 30 min. to 24 hrs; or 30 min. to 12hrs; or 30 min. to 8 hrs; or 30 min. to 4 hrs; or 30 min. to 2 hrs; 2 to48 hrs; or 2 to 24 hrs; or 2 to 12 hrs; or 2 to 8 hrs; or 2 to 4 hrs; 5to 48 hrs; or 5 to 24 hrs; or 5 to 12 hrs; or 5 to 8 hrs; or 5 to 4 hrs;or 5 to 2 hrs; 10 to 48 hrs; or 10 to 24 hrs; or 24 to 48 hrs.

In some embodiments, the ratio of the aqueous medium to the drycomponents or to the composition of the invention (aqueous medium:drycomponents or aqueous medium:composition of the invention) is 0.1-10; or0.1-8; or 0.1-6; or 0.1-4; or 0.1-2; or 0.1-1; or 0.2-10; or 0.2-8; or0.2-6; or 0.2-4; or 0.2-2; or 0.2-1; or 0.3-10; or 0.3-8; or 0.3-6; or0.3-4; or 0.3-2; or 0.3-1; or 0.4-10; or 0.4-8; or 0.4-6; or 0.4-4; or0.4-2; or 0.4-1; or 0.5-10; or 0.5-8; or 0.5-6; or 0.5-4; or 0.5-2; or0.5-1; or 0.6-10; or 0.6-8; or 0.6-6; or 0.6-4; or 0.6-2; or 0.6-1; or0.8-10; or 0.8-8; or 0.8-6; or 0.8-4; or 0.8-2; or 0.8-1; or 1-10; or1-8; or 1-6; or 1-4; or 1-2; or 1:1; or 2:1; or 3:1.

In some embodiments, the precipitate may be rinsed with fresh water toremove halite or the chloride content from the precipitate. The chloridemay be undesirable in some applications, for example, in aggregatesintended for use in concrete since the chloride has a tendency tocorrode rebar. Further, the rinsing of the slurry or the precipitatewith water may cause the vaterite in the composition to shift to morestable forms such as aragonite and calcite and result in the cementedmaterial. For example, the self-cementing composition can be kept in thesaltwater until before use and is rinsed with fresh water that mayremove the halite from the precipitate and facilitate the formation ofthe cemented material.

In some embodiments, such rinsing may not be desirable as it may reducethe yield of the composition. In such embodiments, the precipitate maybe washed with a solution having a low chloride concentration but highconcentration of divalent cations (such as, calcium, magnesium, etc.).Such high concentration of the divalent ion may prevent the dissolutionof the precipitate, thereby reducing the yield loss and the conversionto cemented material.

During the mixing of the composition with the aqueous medium, theprecipitate may be subjected to high shear mixer. After mixing, theprecipitate may be dewatered again and placed in pre-formed molds tomake formed building materials. Alternatively, the precipitate may bemixed with water and is allowed to set. The precipitate sets over aperiod of days and is then placed in the oven for drying, e.g., at 40°C., or from 40° C.-60° C., or from 40° C.-50° C., or from 40° C.-100°C., or from 50° C.-60° C., or from 50° C.-80° C., or from 50° C.-100°C., or from 60° C.-80° C., or from 60° C.-100° C. The precipitate isthen subjected to curing at high temperature, such as, from 50° C.-60°C., or from 50° C.-80° C., or from 50° C.-100° C., or from 60° C.-80°C., or from 60° C.-100° C., or 60° C., or 80° C.-100° C., in highhumidity, such as, in 30%, or 40%, or 50%, or 60% humidity.

The cement product produced by the methods described above may be anaggregate or building material or a pre-cast material or a formedbuilding material. These materials have been described herein.

In yet another aspect, there is provided a system for making the cementproduct from the composition of the invention including (a) an input forthe composition of the invention; (b) an input for an aqueous medium;and (c) a reactor connected to the inputs of step (a) and step (b)configured to mix the composition of the invention with the aqueousmedium under one or more of suitable conditions to make a cementproduct. In some embodiments, the system further comprises a filtrationelement to filter the composition after the mixing step (c). In stillsome embodiments, the system further comprises a drying step to dry thefiltered composition to make the cement product.

FIG. 4 shows an illustrative system embodiment 200 to make the cementproduct from the composition of the invention. In some embodiments,system 200 includes a source for the composition of the invention 210.In some embodiments, the source for the composition includes a structurehaving an input for the composition. Such structure having an inputincludes, but is not limited to, a funnel, a tube, a pipe or a conduit,etc. Any input that can facilitate the administration of the compositionto the reactor 230 is within the scope of the invention. It is wellunderstood that in some embodiments, no such source for the compositionor the structure with an input for the composition is needed, when thecomposition is already present in the reactor 230. In some embodiments,there is provided a source for aqueous medium 220 such as, wateroptionally containing sodium chloride, calcium chloride, magnesiumchloride, or combination thereof or brine. In some embodiments, thesource for the aqueous medium 220 contains an input for the aqueousmedium, such as, but not limited to, a funnel, a tube, a pipe or aconduit, etc. Any input that can facilitate the administration of theaqueous medium to the reactor 230 is within the scope of the invention.It is well understood that in some embodiments, no such source for theaqueous medium or the structure with an input for the aqueous medium isneeded, when the aqueous medium is already present in the reactor 230.

The reactor 230 is connected to the two inputs and is configured to mixthe composition of the invention with the aqueous medium under one ormore of suitable conditions to make a cement product. The one or moresuitable conditions have been defined above. The reactor 230 may beconfigured to include any number of different elements, such astemperature regulators (e.g., configured to heat the water to a desiredtemperature), chemical additive elements, e.g., for introducing chemicalpH elevating agents (such as NaOH) into the water. This reactor 230 mayoperate as a batch process or a continuous process. The system mayoptionally contain a filtration element to filter the composition afterwetting (not shown in FIG. 4).

After the addition of water to the composition in the reactor, thecomposition sets and hardens into the cement product. The cement productmay optionally be dried and cured.

In one aspect, there is provided a method to make a cement product ofdesired compressive strength, including combining a composition of theinvention with an aqueous medium under one or more conditions including,but not limited to, temperature, pressure, time period for setting, aratio of the aqueous medium to the composition, and combination thereof.In some embodiments, the composition includes at least 47% w/w vateriteor at least 10% w/w vaterite and at least 1% w/w ACC. In someembodiments, the composition includes a carbon isotopic fractionationvalue (δ¹³C) of less than −12‰. In some embodiments, the compositionupon combination with water; setting; and hardening, has a compressivestrength of at least 14 MPa. In some embodiments, the method includesoptimizing one or more of the conditions; and allowing the compositionto set and harden into a cement product of desired compressive strength.

The one or more conditions including, but not limited to, temperature,pressure, time period for setting, a ratio of the aqueous medium to thecomposition, and combination thereof, have been described herein. Theoptimization of these one or more conditions includes modifying the oneor more conditions to achieve a cement product of desired compressivestrength. For example, the ratio of the aqueous medium to thecomposition can affect the setting time, hardening time, hydrationreaction, shrinkage, and the compressive strength of the cementedproduct. Therefore, optimization of the ratio of the aqueous medium tothe composition can result in the cement product of desired compressivestrength.

IV. Packages

In one aspect, there is provided a package including the composition ofthe invention. In some embodiments, there is provided a packageincluding a pre-cast or a formed building material formed from thecomposition of the invention. These pre-cast or formed buildingmaterials are as described herein. The package further includes apackaging material that is adapted to contain the composition. Thepackage may contain one or more of such packaging materials. Thepackaging material includes, but is not limited to, metal container;sacks; bags such as, but not limited to, paper bags or plastic bags;boxes; silo such as, but not limited to, tower silo, bunker silo, bagsilo, low level mobile silo, or static upright cement silo; and bins. Itis understood that any container that can be used for carrying orstoring the composition of the invention is well within the scope of theinvention.

In some embodiments, these packages are portable. In some embodiments,these packages and/or packaging materials are disposable or recyclable.

The packaging material are further adapted to store and/or preserve thecomposition of the invention for longer than few months to few years. Insome embodiments, the packaging materials are further adapted to storeand/or preserve the composition of the invention for longer than 1 week,or longer than 1 month, or longer than 2 months, or longer than 5months, or longer than 1 year, or longer than 2 years, or longer than 5years, or longer than 10 years, or between 1 week to 1 year, or between1 month to 1 year, or between 1 month to 5 years, or between 1 week to10 years.

The following examples are put forth so as to provide those of ordinaryskill in the art with a complete disclosure and description of how tomake and use the present invention, and are not intended to limit thescope of what the inventors regard as their invention nor are theyintended to represent that the experiments below are all or the onlyexperiments performed. Efforts have been made to ensure accuracy withrespect to numbers used (e.g. amounts, temperature, etc.) but someexperimental errors and deviations should be accounted for. Unlessindicated otherwise, parts are parts by weight, molecular weight isweight average molecular weight, temperature is in degrees Centigrade,and pressure is at or near atmospheric.

The abbreviations used in the application have an ordinary meaningunless indicated otherwise. Some of the abbreviations are defined below:

ACC = Amorphous calcium carbonate CaCl₂= Calcium chloride CaO = Calciumoxide CaSO₄ = Calcium sulfate DI = Deionized water FT-IR = Fouriertransform infrared spectroscopy g = gram μm = micrometer mL = milliliterM molar MgCl₂ = Magnesium chloride NaCl = Sodium chloride Na₂CO₃ =Sodium carbonate NaF = Sodium fluoride NaOH = Sodium hydroxide NaP =Sodium phosphate Na₂SiO₄ = Sodium silicate OPC = Ordinary Portlandcement ppm = Parts per million RCM = Reactive carbonate minerals SCM =Supplementary cementitious material SEM = Scanning electron microscopyTGA = Thermo-gravimetric analysis XRD = X-ray diffraction

EXAMPLES Example 1 Precipitation

To 1 L tap water was added 5.08 g MgCl₂.6H₂O and 14.71 g CaCl₂.2H₂O. ThepH was maintained at ˜9 using 2M NaOH solution. Carbon dioxide waspassed through the solution. Cloudy white precipitate appeared thatsettled quickly. The precipitate was washed with acetone. The product onfilter paper weighed 1.58 g.

For another sample, to 1 L of tap water, 30 g of NaCl, 2.03 g MgCl₂.6H₂Oand 7.35 g CaCl₂.2H₂O was added. The pH of the solution was maintainedbetween 8-9 using 2M NaOH solution and carbon dioxide. Cloudy whiteprecipitate appeared that settled quickly. The precipitate was washedwith acetone. The product on filter paper weighed 1.60 g.

The products were mixed with water which after setting, hardening andcuring gave cemented material.

Example 2 Preparation of Precursors of Vaterite and Vaterite

In this study, precursors of vaterite were synthesized along withvaterite by freezing and immediate dewatering. Carbon dioxide wasreacted with NaOH to create sodium carbonate and sodium bicarbonate. Tothe sodium carbonate and bicarbonate mixture, was added seawater tointroduce calcium and magnesium ions and to precipitate calcium andmagnesium carbonates. The calcium carbonate was precipitated at pH of8.5-8.8. The precipitated calcium carbonate was a mixture of vateriteand calcite. In addition to precipitating vaterite and calcite, theprecipitate was dewatered fast enough to stabilize pre vaterite forms orthe precursors of vaterite. These precursors of vaterite are differentfrom ACC.

FIGS. 5A-E illustrate SEM images of nanoclusters of particles assemblinginto the vaterite spheres. These nanoclusters are precursors tovaterite. In a typical vaterite precipitation process, stabilization ofthe vaterite may be challenging (owing to high reactivity of vaterite)let alone stabilization of the precursors of vaterite. FIG. 5Fillustrates the formation of vaterite where all the precursor phase hasassembled into well defined framboidal spheres by the time theprecipitate is dewatered and dried. The precursor to vaterite and thevaterite can be utilized as a reactive metastable calcium carbonate forreaction purposes and stabilization reactions, such as cementing.

Similar to the precursor and the vaterite formation, precursor ofaragonite and aragonite itself were also prepared. These crystals weresub-micron to nanoclusters of aragonite needles. Upon activation, theseneedles continued to grow to full size aragonite needles and thencontinued to transform to calcite. The precursor to aragonite and thearagonite itself were prepared using the same protocol as in Example 1except that the ratio of Ca:Mg in the mixture was around 1:4.

Example 3 Precipitation and Transformation of Synthetic Vaterite

Vaterite was synthetically prepared by laboratory precipitation.Synthetic brine was produced by dissolving 110 grams NaCl, 24 gramsCaCl₂, and 5 grams MgCl₂ per liter of Milli-Q deionized (DI) water.Vaterite was precipitated using 75 mL of 2M NaOH per liter of solution,sparging CO₂, stirring with a magnetic stir bar, and monitoring pH tomaintain between 7.5 and 8.5 during the precipitation and end at 9.5.The sample was then filtered and rinsed with deionized water on aBuchner funnel and dried in a 40° C. oven for 24 hours.

Effect of Salt Solution on Transformation:

To induce a polymorphic transformation of vaterite to aragonite, and/orcalcite during cement formation, synthetically precipitated vaterite wasadded to separate sample solutions of Milli-Q deionized water and eachsodium chloride, NaCl; calcium chloride, CaCl₂; magnesium chloride,MgCl₂; and synthetic brine (containing NaCl, CaCl₂, and MgCl₂ asdescribed above) in covered 50 milliliter beakers. A sample was alsoproduced with only deionized water. Scanning electron microscopy (SEM)images of each sample were taken to observe the extent of thetransformation.

Effect of Sodium Hydroxide on Transformation:

To see whether pH has an effect on calcium carbonate cementing, sodiumhydroxide, NaOH, was included into the transformation solution. Twoseparately precipitated synthetic vaterites were placed in 10% solutionsof NaOH with 1:1 solids to water ratios. SEM images of the samples weretaken to observe the effect of NaOH on calcium carbonate cementing.

Effect of Temperature on Transformation:

In order to determine the effect of temperature on the solution-mediatedtransformation of calcium carbonate polymorphs, the deionized water andsalt solutions experiments were repeated in a 110° C. oven. Fortymilliliters of solution was initially present with each sample. Thesamples were covered with aluminum foil in order to maintain the waterlevel for as long as possible. SEM images were taken at the end.

Effect of Water to Solids Ratio on Transformation:

In order to determine an effect of water to solids ratio in the settingof cement, an experiment was performed to determine the smallestquantity of water necessary to allow for the transformation of thesynthetic vaterite. Solutions of synthetic vaterite and deionized waterwere prepared in the solids to water ratios (by weight) of 0.7:1, 1:1,1:2, 1:4, and 1:10.

Effect of Strontium on Transformation:

In order to determine an effect of Sr on the transformation, theexperiments were performed in two separate solutions with Sr at 10 ppmand at 25 ppm.

Precipitation of Synthetic Vaterite by Mixing of Solutions:

Synthetic vaterite was precipitated by the mixing of solutions. Oneliter of augmented seawater (synthetic seawater with 29.2 g CaCl₂*2H₂O)was mixed with 21 g sodium carbonate, Na₂CO₃, and filtered immediatelywith a Buchner funnel. It was then dried in an oven at 40° C. for 24hours. SEM images were taken of vaterite at the end of this period.

Results and Discussion

Precipitation of Synthetic Vaterite:

Vaterite morphology was affected by temperature, pH, pressure, solutioncomposition, precipitation methods, and conditions, such as, rate ofsparging and addition of NaOH. Due to many factors involved in theprecipitation of vaterite, vaterites created by the same methods mayexhibit subtle differences in appearance and reactivity. This minordifference in size and smoothness may be due to a difference in the rateof precipitation or pH. The rate of precipitation may also affect theenthalpy of vaterite transformation. Longer precipitations may result inlower transition enthalpies (Turnbull, A. Geochimica et CosmochimicaActa (1973) 37, 1593-1601).

Although the size of the vaterites created in synthetic precipitationsin this experiment may vary slightly in size, the mean size rangedbetween 12 and 18 micrometers.

Transformation with Salt Solutions:

Interaction of spherical vaterite with deionized water or salt solutionsresulted in various morphologies of calcium carbonate, as illustrated inFIG. 6. Vaterite with deionized water resulted in platelets, rectangularbox-like shapes composed of calcite; spheres and platelets; and spheresand aragonite bundles. Aragonite bundles are groups of rods with aconsistent grain direction.

Upon interaction with synthetic seawater (containing NaCl, CaCl₂, andMgCl₂), vaterite formed aragonite needles, aragonite rods that lackedgrouping or a consistent grain direction. The formation of onlyaragonite needles may be attributed to MgCl₂ acting as an inhibitor tothe transition from vaterite to calcite (Ogino et al. Geochimica etCosmochimica Acta (1987) 51, 2757-2767). For this reason, the transitionmay instead progress almost entirely to aragonite. Given enough time,however, the aragonite can progress to calcite in the form of plateletsor cubes.

When vaterite is placed in NaCl solution, calcite platelet and cubeswere produced. Thermodynamically all reactions may eventually lead tocalcite. Platelets have been observed with deionized water alone. Givenmore time, cubes are expected with vaterite and deionized water. Forthermodynamic reasons, sodium chloride may accelerate the transformationof vaterite into polymorphs of higher stability.

In the case of vaterite with deionized water, spheres were observed incombination with aragonite bundles. Generally, these spheres were hollowand the aragonite bundles were protruding from the surface of thespheres, as depicted below in FIG. 7. The process of precipitation ofthe polymorphs of the invention, is illustrated in FIG. 8. In order forthe center of a sphere to dissolve before the outer shell, the centralmaterial may be desired to be less stable than the shell. A mechanismthat may result in these morphologies is the gradual precipitation ofcalcite nanocrystals onto the surface of vaterite spheres. Becausecalcite is more stable than vaterite, the inner vaterite material beginsto dissolve while the calcite shell remains (Tang et al. CrystalResearch and Technology (2008) 43, 473-478 2008). Aragonite nucleatesand grows in bundles on the surface of these hollowing spheres at theexpense of the dissolving vaterite core due to the process of Ostwaldripening. This process is depicted in steps d-f of FIG. 8. The steps a-ddepict the formation of the nanoclusters of the precursor of thevaterite and their conversion to the vaterite spheres.

In the deionized water experiment, the steps d-f were observed.Additionally, the SEM images revealed that the aragonite bundles brokeoff of the calcite microspheres and detached from each other to formaragonite needles. FIG. 9 outlines the steps involved in thistransformation. Calcite precipitated on the surface of vateritemicrospheres, vaterite dissolved from within the spheres, aragonitebundles precipitated on the surface of the spheres, aragonite bundlesmatured and broke off, aragonite bundles finally broke up into aragoniteneedles, leaving aragonite needles and hollow calcite microspheres.

Transformation with Sodium Hydroxide:

The addition of sodium hydroxide to solution with vaterite inhibitedvaterite transition to calcite such that aragonite needles werepreferentially formed. In addition to the aragonite needles, much matrixmaterial was present that allowed for additional adhesion in the sample.The samples produced with sodium hydroxide were significantly denserthan transformation samples with deionized water or salt solutions. Thematerial was also harder. The addition of sodium hydroxide producedcomparatively a more thoroughly cementing material.

Effect of Temperature on Transformation:

According to thermodynamics, an increase in temperature allows for adecrease in the minimum critical crystal size for growth. Therefore, athigher temperature, smaller crystals are allowed to grow which wouldhave ordinarily been dissolved into solution for the benefit of evenlarger crystals. As illustrated in FIG. 10, higher heating solutionscontaining vaterite during its transition to calcite resulted in smallercrystal growth. The sample that was heated to 110° C. during transitionexhibited significantly smaller crystal sizes than the sample that washeld at room temperature during the transition. The rate at which thewater evaporated from the sample at 110° C. may have had an effect onthe crystal development in addition to temperature alone.

Water to Solids Ratio and Transformation:

Vaterite was not observed to transition to calcite below a 1:1solids:water ratio. The rate of transformation decreased as the amountof water decreased below a 2:1 ratio. The dissolution of vateritecontrols the transformation of vaterite into calcite (Yamaguchi &Murakawa, Zairyo (1981) 30, 856). Rate of transformation may be equal tothe rate of dissolution. Rate of vaterite transformation may increasewith decreasing supersaturation (Spanos & Koutsoukos, J. of CrystalGrowth (1998) 191, 783-790).

Effect of Strontium on Transformation:

Vaterite precipitated with 10 parts per million strontium, exhibitedmore dimples and irregularities whereas vaterite precipitated with 25part per million strontium exhibited a smoother and more uniformsurface.

Precipiation of Synthetic Vaterite by Mixing of Solutions:

Synthetic vaterite precipitated by the mixing of solutions exhibitedmany vaterite microcrystallites that had an aggregation tendency. Asshown in FIG. 11, the microcrystallites aggregated into vaterite spheresknown as framboidal vaterite.

Effects of Sodium Chloride on Transformation:

Sodium chloride caused the transformation of vaterite into calcite ascompared to solution with no sodium chloride (FIG. 12). FIG. 12Aillustrates the transformation of vaterite in DI water at 110° C. for 65hrs and FIG. 12B illustrates the transformation of vaterite in DI waterwith NaCl at 110° C. for 65 hrs.

Results

Vaterite possesses potential for use as a cementitious material oraggregate. As the rate of precipitation of vaterite later affects therate of transformation of vaterite to a more stable phase, vateritesprecipitated from a range of rates could be combined to create a blend.The vaterites in this mixture would begin to transition at differentpoints in time, resulting in a dense matrix of a variety of calciumcarbonate polymorphs.

ACC may be stabilized during precipitation. If ACC is adequatelystabilized to a degree where it could also be packaged and laterinitiated to transform to a polymorph of greater stability, it would beeffective as cement. The additional energy present in ACC will allow forbetter cementing in the polymorphic transition.

More advances may be done in the area of decreasing the amount of waternecessary to initiate a phase transformation. The water to solids ratiomay be reduced to about 0.5 before calcium carbonate alone can be usefulas a cementing material.

Example 4 Preparation of Blended Compositions

This example illustrates various combinations of the vaterite and/or ACCwith other components to prepare the blended compositions of theinvention. Table 1 shows various different types of vaterite andoptionally other polymorph containing compositions that may be mixedwith other components to prepare the blended compositions of theinvention. sCaCO₃ is stabilized calcium carbonate such as calcite andmCaCO₃ is metastable calcium carbonate such as vaterite or ACC. Forexample, mCaCO₃-1 may be mixed with other metastable calcium carbonates(2, 3, and/or 4) and may be mixed with any one or more of the othercomponents such as, NaCl, CaO, CaSO₄, Na₂SiO₄, NaP, and/or NaF.

TABLE 1 Components Amount (%) Proposed properties mCaCO₃-1    0-80metastable CaCO₃ mCaCO₃-2    0-80 metastable CaCO₃ mCaCO₃-3    0-80metastable CaCO₃ mCaCO₃-4    0-80 metastable CaCO₃ NaCl 0.01-5 Toincrease the ionic activity of the solution CaO 0.01-5 pH and Ca²⁺ ionmodifier CaSO₄•0.5H₂O 0.01-5 initial setter CaSO₄•2H₂O  0.001-0.5 seedfor CaSO₄•0.5H₂O Na₂SiO₄ 0.01-5 initial setter NaP 0.01-2 initial setterNaF 0.01-2 initial setter

The compositions prepared by blending the components of Table 1 weremixed with water which after setting, hardening and curing gave cementedmaterial (transformed from 80.9% vaterite and 13.2% calcite to 12.4%vaterite and 83% calcite after 7 days). Some of the examples of thecompositions that were prepared and were subjected to cementing are asfollows:

1 g sub-micron vaterite with 0.25 g pre-reacted for seed; 1 g ofvaterite with 0.25 g pre-reacted for seed; 0.5 g of vatreite; and 2.3 g40% Na₂SiO₃ with a dispersant to reduce water demand.

1 g sub-micron vaterite; 1 g vaterite; 0.9 g of another blend ofvaterite; 0.1 g CaO; 0.1 g NaF; 0.1 g NaP; 0.35 g plaster of Paris; 0.05g Gypsum; 0.1 g CaCO₃; and 0.5 g NaOH, Adva (plasticizer), and NaCl.

The two compositions, when mixed with water, set and hardened intocement.

Example 5 Transformation of Vaterite Compositions into Cement Material

This study shows preparation of various compositions of the inventionand their transformation into cement.

Composition 1: 1.3 g vaterite; 1.3 g another blend of vaterite; 0.5 gball milled version of the vaterite; 0.5 g Na₂CO₃; 0.15 g Ca(OH)₂; 0.35g CaCl₂; and 1.15 g CaCO₃.

Composition 2: 1 g vaterite; 1 g another blend of vaterite; 0.5 g stillanother blend of vaterite (calcite for seeding); Na₂SiO₃; and 5 drops ofAdva until paste formation took place.

Composition 3: 1 g vaterite; 1 g another blend of vaterite; 0.2 gNa₂CO₃; 0.6 g Ca(OH)₂; and 10% NaCl in water until paste was formed.

These compositions were blended to make a paste which was transformedinto a cube. SEM's of the dried paste showed transformation of vateriteto calcite and the result was a hard cemented material.

Example 6 Compressive Strength of the Cement Material Formed fromVaterite Compositions

Various composition of vaterite with other components were prepared andtested:

Composition 1: 10 g vaterite; 6 g sodium silicate; and 6 g water.

Composition 2: 10 g vaterite; 1 g sodium silicate; and 6 g water.

Composition 3: 10 g vaterite; 2 g sodium silicate; and 5 g water.

Composition 4: 10 g vaterite; 4 g sodium carbonate solution; and 2 gwater.

Composition 5: 10 g vaterite; 3 g sodium carbonate; 2 g sodium silicate;and 2 g water.

Composition 6: 10 g vaterite; 5 g water; and 1 g 2 M sodium hydroxide.

Composition 7: 10 g vaterite; 4 g water; 2 g sodium silicate; and 2 g 2M sodium hydroxide.

Composition 8: 10 g vaterite; 2 g sodium carbonate; and 6 g water.

Composition 9: 30 g vaterite and 12 g tap water.

All the compositions were stored at 40° C. overnight in cube molds whichthen resulted in cubes after curing.

The cubes prepared from these compositions were subjected to compressivestrength test. Table 2 shows the compressive strength of 10 cubesprepared from composition 9.

TABLE 2 Cubes Compressive strength (psi) 1 498.6 2 434.7 3 434.7 4 626.45 639.45 6 460.35 7 611.1 8 508.95 9 575.1 10 720

Example 7 XRD Pattern of the Compositions

This example demonstrates analysis of vaterite or other polymorphs inthe crystal of the compositions, using XRD pattern. FIGS. 13-18illustrate the diffraction pattern of the crystals that arepredominantly vaterite (FIGS. 13-15), predominantly mixed carbonatephases (FIG. 16), and predominantly calcite (FIGS. 17-18).

Example 8 Compressive Strength of the Compositions Combined withPortland Cement

In this study, the SCM composed of calcium carbonate phases of theinvention was tested as a 20% replacement for Portland cement inmortars. The results indicated that the compressive strength and theflow of SCM combined with Portland cement were comparable to that ofPortland cement mortars. In this study, in addition to mortar testing,compositional and physical characteristics of the materials in pastewere also explored. Finally the CO₂ sequestration method and the originof the CO₂ were confirmed using carbon isotope measurements.

The process described in this study captured and converted, withoutcostly gas separation, the carbon dioxide from large point sources suchas coal- or gas-fired power plants to generate carbonate minerals. As anadded benefit, these minerals were used in the built environment ascement, SCM, or aggregates, thereby enabling safe, permanent andeconomical storage of CO₂ and reduction in the global CO₂ footprint ofconcrete.

This study focused on the use of reactive carbonate minerals (referredto as RCM in the rest of the study) as an SCM. As defined above, it isunderstood to the skilled artisan that SCM may be reactive ornon-reactive with the Portland cement. Described below arecharacteristics of RCM as well as the performance of this material as areplacement for Portland cement in mortar. Additional informationrelative to the reactivity of the material in the cement paste isprovided.

Process

The process used flue gas, a source of divalent cations (e.g., Ca²⁺ orMg²⁺) and a source of alkalinity (FIG. 19). The flue gas originated froma gas or coal-fired power plant and could be used raw (i.e., before theremoval of other pollutants such as SOx and NOx). This flue gas wasdirected into a gas-liquid contacting system (“absorber”), where the CO₂dissolved into the water and formed a combination of carbonic acid,bicarbonate, and carbonate anions. The relative ratio of these CO₂species in solution can be controlled by addition of an alkaline sourceto promote a high carbonate ion level. These carbonate ions combinedwith divalent cations to precipitate carbonate minerals in the form ofslurry.

After dewatering and further processing of this slurry, the carbonateminerals can be used in various applications in the built environment,e.g. as SCM in concrete or multi-purpose aggregate for concrete,asphalt, road base, and structural fill applications. This beneficialreuse aspect is a quality that makes the process economically viableamongst carbon capture and sequestration methods. Further evaluationsindicated that this process is less energy intensive than other forms ofcarbon treatment.

Material Characteristics

The RCM is composed of dry powder of calcium carbonate polymorphs, suchas, vaterite, calcite, and amorphous calcium carbonate.

The extent of CO₂ mineralization was determined by inorganic carbonCoulometry and the determination of CO₂ origin was carried out throughδ¹³C isotope analysis. The carbonate mineral phases were identified byX-ray diffraction (XRD), and Fourier transform infrared spectroscopy(FT-IR). Chemical composition of the material was determined using X-Rayfluorescence (XRF) on pressed pellets and total loss on ignition wasobtained by thermo-gravimetric analysis (TGA).

The RCM contained up to 40% CO₂ (91% CaCO₃) and a mixture of vaterite tocalcite in the crystalline portion of the material. The origin of thisCO₂ could be traced back to its source by following the carbon isotopefractionation between ¹²C (“light carbon”) and ¹³C (“heavy carbon”)(Mook, W. G. Netherlands Journal of Sea Research, Vol. 20 (2/3), 1986,pp. 211-223).δ¹³ C=(R _(SAMPLE) /R _(STANDARD)−1)*1000‰ with R═ ¹³ C/ ¹² C and R_(standard) set as the value of the Vienna-PeeDee Belemnite standard(V-PDB).

Marine carbonates contain more of the heavy carbon whereas coal andnatural gas are composed of predominantly light carbon. Thus, powerplant CO₂ emissions have relatively low δ¹³C values. This isotopicallylight carbon signature is transferred to the produced carbonate mineralswith a δ¹³C value of <−25‰ (Constantz, B., “Sequestering CO₂ in theBuilt Environment,” 2009, Trans. American Geophysical Union FallMeeting, Poster session 90(52), Fall Meet. Suppl., Abstract U11A-0013San Francisco). Typical limestones have δ¹³C values ranging from −4.0 to+3.0 depending on their origin. These differences in fractionation ratiothough helpful to track the origin of our carbon dioxide, are small anddo not affect the properties of the concrete.

In addition to the total chloride content provided by XRF, analyses werecarried out to provide the soluble chloride content. Water solublechloride-ion content showed that the total chloride content was lowerthan 0.1% by weight which satisfies the prestressed concreterequirements of ACI 318 for corrosion robustness (ACI 318-08: BuildingCode Requirements for Structural Concrete and Commentary). XRF alsoshowed that the equivalent alkali content (Na₂O_(eq)) was lower than0.6% thus minimizing risks of alkali-silica reaction.

Finally physical characteristics such as particle size distribution andsurface area were determined using a laser diffraction analyzer and aBET gas adsorption analyzer respectively. The specific surface area wasin the order of a few m²/g and the particle size distribution wasunimodal with particles ranging in diameter from 1 to 30 μm (FIG. 20).

Experimental

Further evaluated was the impact on mortar performance (compressivestrength) of a partial replacement of Portland cement by RCM and thereactivity of RCM with the cement paste. Two RCM materials of equivalentcompositions were tested: RCM1 and RCM2. The RCM1 composition had 49.7%vaterite, 48.5% calcite, and 1.8% halite and RCM2 composition had 72.6%vaterite, 24.7% calcite, and 2.8% halite. The stability of CO₂sequestration in the mortar samples was also investigated.

Reference samples were prepared using either: 100% Portland cement, ablend of 80% Portland cement and 20% fly ash, or a blend of 80% Portlandcement and 20% commercial grade ground calcium carbonate (GCC). Thecement used was a type II/V cement. The type of fly ash used wascommercially available as class C (FAC) or class F (FAF). The groundcalcium carbonate was obtained from a commercial source and was mostlycomposed of calcite with traces of dolomite, based on its origin(limestone). The elemental composition of these materials is given inTable 3 along with that of the RCM.

TABLE 3 Elemental composition of the mix components as determined by XRF(unit: weight % of oxide equivalent) Na₂O MgO Al₂O₃ SiO₂ SO₃ Cl K₂O CaOFe₂O₃ OPC4-3 0.00 0.88 4.00 18.20 2.38 0.07 0.20 61.78 3.99 Fly ash C3.24 8.38 17.32 27.69 2.32 0.05 0.35 30.28 5.62 Fly ash F 1.79 2.96718.97 49.59 0.33 0.02 1.18 11.08 4.94 GCC 1.24 3.16 0.95 2.84 0.05 0.320.24 56.70 0.29 RCM1 or Less Up to RCM2 than 0.1% 56%Paste Samples for Setting Time Determination

Pastes of normal consistency were prepared following ASTM C305 (ASTMStandard C305-06, 2006, “Standard Practice for Mechanical Mixing ofHydraulic Cement Pastes and Mortars of Plastic Consistency,” ASTMInternational, West Conshohocken, Pa., 2003, DOI: 10.1520/C0305-06,www.astm.org.) and start of setting was determined using the Vicatneedle (ASTM C191 (ASTM Standard C191-08, 2008, “Standard Test Methodsfor Time of Setting of Hydraulic Cement by Vicat Needle,” ASTMInternational, West Conshohocken, Pa., 2008, DOI: 10.1520/C0191-08,www.astm.org.)) as well as isothermal calorimetry.

Mortar Samples for Flow and Compressive Strength Measurements

Mortar specimens prepared at w/c=0.49 with a blend of 80% Portlandcement and either 20% RCM (mix B) or 15% RCM/5% fly ash (mixes F and G)were compared to reference mixes A, C, D, and E as shown in Table 4.These mortars were prepared following ASTM C305 mixing procedure usingASTM C778 graded sand. The flow of fresh mortar (w/c=0.49) wasdetermined by the flow table method as described in ASTM test C 1437(ASTM C 1437-07, 2007, “Standard Test Method for Flow of HydraulicCement Mortar,” ASTM International, West Conshohocken, Pa., 2003, DOI:10.1520/C1437-07, www.astm.org).

TABLE 4 Mix formulations studied OPC II/V RCM1 FAC FAF GCC Mix A 100% Mix B 80% 20% Mix C 80% 20% Mix D 80% 20% Mix E 80% 20% Mix F 80% 15% 5% Mix G 80% 15%  5%

All specimens were cured in a 98% relative humidity chamber at 23° C.After 24 h, they were removed from their mold and then cured in a limebath in a water chamber at 23° C. until their testing date (1, 7, and 28days).

Pastes Samples for Reactivity Study

The impact on hydration product chemistry of partially replacingPortland cement with the RCM was also investigated during this study.Paste samples were prepared at w/c=0.80 with 20% of the Portland cementreplaced by RCM. Reference samples were prepared using 100% Portlandcement or a blend of 80% Portland cement and 20% ground calciumcarbonate replacement. During the first 4 hours, the hydration wasinterrupted using an acetone rinse and vacuum filtering to study thenature and morphology of hydration products. Additional samples werecovered to avoid excessive carbonation and cured at room temperature forup to 28 days. After 1, 7 and 28 days, a sample was crushed finely andrinsed with acetone over vacuum to remove free water.

Results and Discussion

Product Performance

Setting Time

The setting time measurements, at normal consistency as well as theisothermal calorimtry tests carried out at w:cm=0.50, indicated that thepartial replacement of Portland cement by RCM had no impact on the startof the setting.

Water Demand and Compressive Strengths

Typical flow measurements obtained for the different mix formulationsstudied are reported in Table 5. These results indicated that thepartial replacement of Portland cement by the RCM lead to comparablerheological behavior in mortar as the reference Portland cement or flyash/Portland cement mortars.

Table 5 shows the compressive strength developed from 1 to 28 days.Presence of RCM was beneficial for compressive strength at early age (1and 7 days) as it showed higher strength than mixes that did not containRCM. By 28 days, the compressive strengths obtained for all mixes butmix E (obtained from GCC) were comparable. The 20% RCM of the inventionwhen mixed with Portland cement gives superior compressive strength at28 days, as compared to 20% of ground calcium carbonate mixed withPortland cement.

TABLE 5 Water demand and compressive strength development for variousSCM replacements Compressive strength (psi) Mix Formulation Flow (%) 1day 7 days 28 days A 100% OPC 108% 1900 4350 5510 C 20% FAC 113% 17504080 5260 D 20% FAF 110% 1390 3490 5020 B 20% RCM1 103% 2220 4460 5460 F15% RCM1-5%  94% 1970 4010 5170 FAC G 15% RCM1-5% 119% 1950 3670 5060FAF E 20% GCC 106% 1260 3135 4010

Table 6 and FIG. 21 show the dose effect of another RCM of similarcomposition on water demand and compressive strength development until28 days. The beneficial effect of RCM substitution was maintained up toa replacement level of 20%.

TABLE 6 Water demand and compressive strength development for variousreplacement rates of Portland cement by RCM Compressive strength (psi)Formulation Flow (%) 1 day 7 days 28 days 100% OPC 108% 1900 4350 551010% RCM2  95% 2330 4820 5360 15% RCM2 119% 2150 4620 5500 20% RCM2 112%1930 4100 5090 25% RCM2 117% 1800 3890 4600Product Interaction with Portland Cement

The RCM of the invention is composed of calcium carbonate polymorphs.Calcite in ground limestone is typically considered as a filler inPortland cement hydration, participating to a limited extent (1-5%) inthe hydration reactions by forming analogs of calcium alumino-sulfatehydrates in which the sulfates are replaced by carbonates (Voglis et al.Cement & Concrete Composites, Vol. 27, 2005, pp. 191-196; Matschei etal. Cement and Concrete Research, Vol. 37, 2007, pp. 551-558; Lothenbachet al. Cement and Concrete Research, Vol. 38, 2008, pp. 848-860; Hawkinset al. EB227, Portland Cement Association, Skokie, Ill., USA, 2003, 44pages; and Feldman et al. Journal of the American Ceramic Society, Vol.48, No. 1, 1965, pp. 25-30). Carbonates are shown to enter in thecomposition of calcium silicate hydrates and lower the Portlanditecontent.

XRD, FT-IR and TGA results of this study obtained for paste specimen, onwhich the hydration was halted at different ages ranging from a fewminutes to 28 days, indicated that the presence of the RCM may not alteror slow the hydration reactions of the Portland cement. The sequence offormation of hydrates (portlandite, ettringite, etc.) is similar,whether the RCM is present or not. SEM observations illustrate that thepresence of the RCM in the paste does not modify the morphology of thePortland cement hydrates.

Stability of CO₂ Sequestration

Carbon isotopic measurements were carried out on mortar samples in whichthe cementitious materials comprised 80% OPC and 20% RCM and which werecured for 90 days in normal laboratory air atmosphere. The goal was todetermine if the CO₂ sequestered in the RCM through the mineralizationprocess was still present in the mortar and whether it had been replacedby CO₂ issued from sample carbonation. As shown in Table 7, the low δ¹³Cvalues confirm that the CO₂ present in the mortar samples originatedfrom the flue gas and not from air carbonation.

TABLE 7 Tracing of ¹³C/¹²C isotopic ratios in RCM formation and use assupplementary cementitious material OPC/RCM Control OPC Material CoalFlue gas RCM mortar mortar OPC δ¹³C −25.7 −24.4 −30.5 −26.2 −17.5 −4.5(‰ vs. PDB)

Furthermore, the hydrated phases, containing CO₂ formed in mortars madewith the RCM of the invention, were similar to those formed in mortarsmade with ground limestone. Similar durability properties shouldtherefore be expected. These results confirm that the production of RCMfrom flue gas will be a means to sequester CO₂ in the built environmentfor extended periods of time and will result in durable cement.

It is anticipated that RCM will be introduced in regional markets, localto production, at a price point on parity with fly ash. The economics oftransportation as well as supply and demand control the price of qualitybulk fly ash and slag. However, it is expected that true RCM pricing maybe much more complex. It is foreseeable that Carbon Cap-and-tradelegislation or tighter Mercury emission standards may reduce the pricingof the RCM product.

Example 9 Synthesis and Stability of ACC

In this study, the synthesis and stability of amorphous calciumcarbonate (ACC) synthesized with different solutions having differentCa:Mg ratios was investigated. Understanding the synthesis conditionsfor ACC may help to define the amorphous/calcium carbonate polymorphprecipitation regions and generate standard material for analyticalmethod development. Investigating the stability of this material canindicate conditions, e.g., shelf-life, reactivity, etc. of ACC that maybe a component of the composition of the invention.

It was found that a Ca:Mg ratio of 0.1 yielded ACC of long-termstability (with halite due to rinsing step). Having no Mg²⁺ in solutionled to a transformation to either: a mixture of calcite, vaterite, andaragonite or calcite and vaterite. At a Ca:Mg ratio of 0.3, the ACCtransitioned to primarily calcite with some trace of aragonite. At theCa:Mg ratio of 0.2, a stable ACC material was formed. This material wasfound to be stable in low humidity conditions for over a year.

Without being limited by any theory, it is proposed that concentrationsof other ions in solution may contribute to some of the observeddifferences in crystalline polymorphs and the stability of the ACCsynthesized.

Materials and Equipment

Vacuum filtration setup (Whatman No. 1 filter); Chilled water bath; andNa₂CO₃, MgCl₂, CaCl₂.

Experimental

An initial recipe of using 5 mM CaCl₂ and 5 mM Na₂CO₃ was used for adouble decomposition method of forming ACC. A sample using thisprocedure was centrifuged to a thick slurry and was measured by Raman inthe glass vial sample port on the Raman to compare the standard ACCspectra with reported literature values (Ajikumar et al., Crystal Growthand Design, (2005) Vol 5, No, 3, pages 1129-1134; Kontoyannis et al, TheAnalyst, 2000; Raz, et al, Biol. Bull. (2002) 203, pages 269-274; andWeiner et al, Connective Tissue Research, (2003) 44 (Supl 1), pages214-218).

A second matrix was chosen to investigate the effect of the ratio ofCa:Mg in solution on ACC formation and stability (Table 8). ACC 7-9conditions were the same ratio as ACC2, however rinsing and mixing stepswere varied slightly to optimize the rinsing procedure.

TABLE 8 Amounts of reactants used to investigate Ca:Mg ratio in ACCsynthesis Na₂CO₃ MgCl₂ CaCl₂ Ca:Mg Sample g mL H₂O M g mL H₂O M g mL H₂OM (750 mL) ACC1 14.39 250 0.54 27.42 250 0.54 2.21 250 0.06 0.111 ACC214.39 250 0.54 13.71 250 0.27 2.21 250 0.06 0.222 ACC3 14.39 250 0.540.00 0.00 0.00 2.21 250 0.06 N/A ACC4 14.39 250 0.54 0.00 0.00 0.0019.85 250 0.54 N/A ACC5 14.39 250 0.54 81.5 250 1.61 19.85 250 0.54 0.34ACC6 14.46 250 0.54 27.42 250 0.54 6.63 250 0.18 0.333 ACC7 14.39 2500.54 13.71 250 0.27 2.21 250 0.06 0.222 ACC8 14.39 250 0.54 13.71 2500.27 2.21 250 0.06 0.222 ACC9 14.39 250 0.54 13.71 250 0.27 2.21 2500.06 0.222

Every chemical was dissolved thoroughly in DI water and diluted to 250mL volume in a Pyrex volumetric flask, and placed in ice water (˜5° C.)for 20-30 minutes. The solutions were then mixed and stirred vigorouslyon a magnetic stir plate for 60 seconds and immediately filtered throughWhatman No. 1 filter paper using vacuum a filtration setup. Theprecipitate was rinsed in some cases with just alcohol (isopropylalcohol (IPA) and ethanol were investigated) and in some cases firstwith chilled DI water and then with alcohol. The precipitate wasimmediately transferred into a 15 mL tube and placed first in liquidnitrogen for a few hours to rapidly freeze the sample and thentransferred to the lyophilizer for overnight drying. The samples werethen prepared for characterization by XRD. All samples were kept in adesiccator in between analyses (˜0-25% RH (relative humidity)).

Results and Discussion

XRD analysis was performed on the precipitates and the products fromexperiments 2, 5, 8 and 9 showed the characteristics expected for ACC(Dandeu et al., Chem. Eng. Technol., (2006) 29, No. 2, Pages 221-225;Lam et al, Cryst. Eng. Comm., 2007; Ajikumar et al., Crystal Growth andDesign, (2005) Vol 5, No, 3, pages 1129-1134; and Kontoyannis et al, TheAnalyst, 2000).

The precipitates from these experiments were thoroughly rinsed firstwith chilled DI water and then with chilled ethanol. The main differencebetween experiment 8 and 9 was that in exp. 8, a well-mixed solution ofCaCl₂/MgCl₂ was added to the solution of CaCO₃, and in experiment 9 thereverse was done. The experiment 8 may be preferred because theprecipitate yield was better and it was 40 g versus 30 g from that ofexperiment 9. It was also found that rinsing with chilled DI waterfollowed by chilled ethanol was the desired rinse step of the methodsinvestigated. Additional investigation of the mixing and rinsing stepsmay be done to determine whether chilling is necessary and to optimizethe mixing. The initial XRD characterization of 2, 5, 8, and 9 is shownin FIG. 22.

In the case of protocols 1, 6 and 7, halite was the only crystallinephase detected. In 7, upon rinsing the dried precipitate with chilled DIwater, the detectable halite content was removed. This may indicate thatif the conditions are appropriate (time and temperature), some stabilityof a dried sample in contact with fresh water is observed.

Samples from protocols 3 and 4 showed the formation of crystallinecalcium carbonates upon analysis. The results of 3 will be discussed inthe stability section below. In the sample from 4, calcite, vaterite andhalite were present in the sample (FIG. 23). Raman of the doubledecomposition sample (3, 5) yielded spectra that matched expectedliterature spectra for ACC.

Stability

The stability of protocols 3, 5, and a mixture of samples produced fromprotocols 2, 7 (rinsed), 8, and 9 was investigated. As noted above, inprotocol 3, the primary calcite peak was visible upon initial analysis.After 4 days, aragonite, calcite, and vaterite, were present.

In protocol 5, the initial analysis showed no signs of crystallinematerial, and after 4 days well formed calcite, with possibly smallamounts of aragonite was observed (FIG. 24).

Samples 2, 7 (rinsed), 8, and 9 were all synthesized with the same Ca:Mg(with some processing differences) and were blended to create a largersample. This sample was analyzed over time. The ACC remained stable forover a year in the low humidity conditions (FIG. 25).

Raman of this sample was being run as a comparison to the Raman spectraacquired from the original double decomposition method.

Equal volume of solutions of 0.27 M MgCl₂.6 H₂O/0.06 M CaCl₂.2 H₂O/0.54M CaCO₃ seems to be one of the suitable mixture for synthesizing ACC inthis study (in terms of yield and stability). It may also be desirableto rinse the precipitates well with first DI water and then with alcoholto wash out any sodium chloride from the precipitate. The stability ofthe ACC created by this method was greater than that of the othersolution ratios tested, being stable for over a year in low humidityconditions. Different synthesis conditions also indicated differentcrystallization pathways.

Example 10 Vaterite Precipitation Matrices

In this study, an effect of a ratio of Ca:Mg in the precipitation of thecement material from synthetic hard brine was investigated. A 4 Lreactor was filled with brine containing a higher concentration ofcalcium than magnesium (as compared to seawater). A stream of carbondioxide and compressed air was passed through the solution along with anaddition of the base when it resulted in the precipitation of thepowdered material. The powdered material was found to contain vateriteand the amount of vaterite obtained was found to be dependent on theratio of calcium with magnesium. Table 9 demonstrates that the amount ofvaterite in the precipitated material increased with increase in thecalcium concentration. Therefore, the amount of vaterite in thecomposition may be modulated by the ratio of Ca:Mg in the solution.

TABLE 9 Ca:Mg XRD 4:1 3:1 2:1 Vaterite 91% 20% — calcite  8% 79% —(MgCa)CO₃ 99%

Example 11 Vaterite Vs. Calcite Precipitation Across a Range ofPrecipitation Conditions

In this study, an effect of precipitation conditions in theprecipitation of the cement material from synthetic hard brine wasinvestigated. Solutions containing various concentrations of Ca²⁺ ions(0.01 mol/L, 0.05 mol/L; and 0.10 mol/L) were prepared by addinganhydrous Na₂CO₃ or 50% NaOH and CO₂ to 0.2 mol/L Ca²⁺ solution. Table10 shows a summary of the concentrations.

TABLE 10 Total CO₂ 50% Target Yield mineralized Na₂CO₃ NaOH [Ca²⁺]_(f)[Ca²⁺]_(f) pH_(f) % C (g/L) (g/L) 42.40 g — 0.10 0.10 7.76 9.6 14.154.98 63.60 g — 0.05 0.05 7.98 9.7 17.83 6.34 80.56 g — 0.01 0.014 8.3510.4 22.47 8.57 — 64 g 0.10 0.11 6.66 9.9 12.53 4.55 — 96 g 0.05 0.048.35 9.9 17.40 6.32 — 108.80 g    0.01 0.015 7.94 10.4 19.36 7.38Initial Ca²⁺ concentration = 0.2 mol/L for all experiments Initial andfinal Mg²⁺ concentrations = 0.04-0.05 mol/L for all experiments Finalalkalinity = 3-9 mmol/kg for all experiments pH = 8.0-8.5 during baseaddition

The addition of anhydrous Na₂CO₃ vs. 50% NaOH and CO₂ to the calciumsolution resulted in the formation of precipitates with varying vateritecontent. Table 11 shows the amount of vaterite formed in theprecipitation conditions for three sets of experiments. Higher vateritecontent was observed in the precipitate when the solution of 50% NaOHand CO₂ was added to the calcium solution.

TABLE 11 Experiment 1 Experiment 2 Experiment 3 50% NaOH 50% NaOH 50%NaOH XRD Na₂CO₃ and CO₂ Na₂CO₃ and CO₂ Na₂CO₃ and CO₂ vaterite 43% 85%31% 80% 32% 83%  calcite 46%  8% 61%  5% 65% 4% aragonite — — — 12% — 9%[Ca²⁺]_(i) 0.2M 0.2M  0.2M  0.2M  0.2M  0.2M [Ca²⁺]_(f) 0.1M 0.1M 0.05M0.04M 0.01M 0.01M

Example 12 Vaterite Vs. Calcite Precipitation in Old Brine and FreshBrine

A batch of old brine and fresh brine with varying concentration ofNa₂CO₃ solution was added to the calcium ion containing solution in avarying duration of times. Old brine was made 6 days before theexperiment and was filtered two days before the experiment to remove anyprecipitated gypsum from the solution. Fresh brine was made one daybefore the experiments and was filtered on the same day as theexperiments. Table 12 shows a summary of the concentrations.

TABLE 12 Total CO₂ Brine Base [Ca²⁺]_(f) Yield mineralized type Na₂CO₃duration pH_(f) (mol/L) % C (g/L) (g/L) Old  50%* 10 min. 7.78 0.1 10.2611.43 4.30 fresh  50%* 10 min. 8.03 0.1 9.69 11.05 3.93 Old 25% 10 min.7.67 0.1 10.50 11.23 4.32 fresh 25% 10 min. 7.54 0.1 9.55 11.10 3.89 Old25%  4 min. 7.88 0.1 10.41 11.43 4.36 fresh 25%  4 min. 7.70 0.1 10.2911.09 4.18 Initial Ca²⁺ concentration = 0.2 mol/L for all experimentsInitial and final Mg²⁺ concentrations = 0.04-0.05 mol/L for allexperiments Final alkalinity = 2-5 mmol/kg for all experiments pH =8.0-8.5 during base addition *Na₂CO₃ is not soluble in solution at 50%

Table 13 shows the amount of vaterite formed in the precipitationconditions for three sets of experiments. Highest vaterite content wasobserved in the precipitate with 25% Na₂CO₃ in old brine with 10 min.base addition. Vaterite content was comparable in Experiment 4.

TABLE 13 Experiment 1 Experiment 2 Experiment 3 Experiment 4 50% Na₂CO₃50% Na₂CO₃ 25% Na₂CO₃ 25% Na₂CO₃ 25% Na₂CO₃ 25% Na₂CO₃ 50% NaOH + CO₂25% Na₂CO₃ in old brine + in fresh brine + in old brine + in freshbrine + in old brine + in fresh brine + in fresh brine + in old brine +XRD 10 min addition 10 min addition 10 min addition 10 min addition 4min addition 4 min addition 30 min addition 10 min addition vaterite 86%80% 94% 86% 90% 81% 94% 94% calcite  5% 16%  4%  7%  6% 15%  4%  4%[Ca²⁺]_(i) 0.2M 0.2M 0.2M 0.2M 0.2M 0.2M 0.2M 0.2M [Ca²⁺]_(f) 0.1M 0.1M0.1M 0.1M 0.1M 0.1M 0.1M 0.1M

Example 13 Zeta Potential Measurement

1.5 g of the vaterite containing compositions were dissolved in 150 g ofDI (1% solid slurry). The mixture was stirred and the probes for zetapotential, pH, and temperature were inserted into the mixture. Table 14shows the particle size (PS), the vaterite and the calcite content, andthe zeta potential of the three samples that were tested.

TABLE 14 Zeta Sample Vaterite Calcite Mean PS pH potential MC048-09-00683% 17% 5.9 μm 10.3 42.7 mV MLPP0023-06-110 76% 24% 14.2 μm  10.5 12.9mV MLPP0023-24-032 84% 16% 7.7 μm 10.2 25.6 mV

FIG. 26 demonstrates that the composition with highest zeta potentialhad finely dispersed particles (FIG. 26A); the composition with lowestzeta potential had most agglomeration of the particles (FIG. 26B); andthe composition with intermediate zeta potential had agglomeration butto a lesser extent (FIG. 26C). The compressive strength of the hardenedmaterial also showed a difference in the compressive strength when 20%of the composition was mixed with 80% OPC. FIG. 27 illustrates that thecomposition with highest zeta potential showed highest compressivestrength as compared to the composition with lower zeta potential.

The composition with highest zeta potential and small particle size wasalso found to have a high cumulative heat indicating higher reactivity(see B in FIG. 28).

Example 14 Brines with Carbonates

In this study, various brines were subjected to different precipitationconditions and the precipitated material was analyzed. The brinesincluded Onondaga brine, seawater based synthetic brine with NaCl(seawater+27.9 g/L CaCl₂+99.13 g/L NaCl), seawater based synthetic brinewithout NaCl (seawater+27.9 g/L CaCl₂), and deionized water basedsynthetic brine (deionized water+29.4 g/L CaCl₂). Onandaga brine is ahalite brine, with saturation ranging from 45 to 80%, that lies withinglacial sediments that fill the Onondaga Trough, a bedrock valleydeepened by Pleistocene glaciation near Syracuse, N.Y. State, USA. Thesebrines were treated with 15% CO₂+50% wt NaOH, Na₂CO₃ anhydrous, 50% wtNa₂CO₃ solution, and 25% wt Na₂CO₃ solution.

Onondaga brine on treatment with 15% CO₂ and 2M NaOH resulted in 91%vaterite in the precipitated material. The initial ratio of Ca:Mg([Ca²⁺]_(i):[Mg²⁺]_(i)) was about 4:1. Table 15 shows the concentrationsof the initial and final ions in the solution.

TABLE 15 Onondaga Brine (High Na⁺) [Ca²⁺]_(i) 48.63 mM [Mg²⁺]_(i) 10.63mM [Ca²⁺]_(f) 3.54 mM [Mg²⁺]_(f) 9.37 mM Alk_(f) 102.1 mM eq vaterite91%  calcite 8% halite 1%

Seawater based synthetic brine with NaCl (seawater+27.9 g/L CaCl₂+99.13g/L NaCl) when treated with 15% CO₂ and 50% wt NaOH resulted in 96%vaterite content in the precipitated material. The initial ratio ofCa:Mg ([Ca²⁺]_(i):[Mg²⁺]_(i)) was about 4:1. Table 16 shows theconcentrations of the initial and final ions in the solution.

TABLE 16 Synthetic brine (seawater) [Ca²⁺]_(i) 0.20M [Mg²⁺]_(i) 0.05M[NaCl]_(i)  2.1M [Ca²⁺]_(f) 0.10M [Mg²⁺]_(f) 0.05M vaterite 96%  calcite3% halite 1%

Seawater based synthetic brine with NaCl (seawater+27.9 g/L CaCl₂+99.13g/L NaCl) when treated with Na₂CO₃ anhydrous resulted in only 43%vaterite content in the precipitated material. The initial ratio ofCa:Mg ([Ca²⁺]_(i):[Mg²⁺]_(i)) was about 4:1. Table 17 shows theconcentrations of the initial and final ions in the solution.

TABLE 17 Synthetic brine (seawater) [Ca²⁺]_(i) 0.20M [Mg²⁺]i 0.05M[NaCl]_(i)  2.1M [Ca²⁺]_(f) 0.10M [Mg²⁺]_(f) 0.05M Alk_(f) 3.4 mM eqvaterite 43% calcite 46% halite 11%

When seawater based synthetic brine (seawater+27.9 g/L CaCl₂+99.13 g/LNaCl) was treated with 50% wt Na₂CO₃, it resulted in 90% vateritecontent in the precipitated material. The vaterite content seemed toincrease when the sodium carbonate was not anhydrous. The initial ratioof Ca:Mg ([Ca²⁺]_(i):[Mg²⁺]_(i)) was about 4:1. Table 18 shows theconcentrations of the initial and final ions in the solution.

TABLE 18 Synthetic brine (seawater) [Ca²⁺]_(i) 0.20M [Mg²⁺]_(i) 0.05M[NaCl]_(i)  2.1M [Ca²⁺]_(f) 0.10M [Mg²⁺]_(f) 0.05M Alk_(f) 3.3 mM eqvaterite 90%  calcite 6% halite 4%

When seawater based synthetic brine (seawater+27.9 g/L CaCl₂+99.13 g/LNaCl) was treated with 25% wt Na₂CO₃, it resulted in 94% vateritecontent in the precipitated material. The vaterite content increasedwith 25% wt Na₂CO₃ as compared to 50% wt Na₂CO₃. This could be due tohigher solubility of Na₂CO₃ in the solution when it is 25% wt Na₂CO₃.The 50% wt Na₂CO₃ is sparingly soluble in water. The initial ratio ofCa:Mg ([Ca²⁺]_(i):[Mg²⁺]_(i)) was about 4:1. Table 19 shows theconcentrations of the initial and final ions in the solution.

TABLE 19 Synthetic brine (seawater) [Ca²⁺]_(i) 0.20M [Mg²⁺]_(i) 0.05M[NaCl]_(i)  2.1M [Ca²⁺]_(f) 0.10M [Mg²⁺]_(f) 0.05M Alk_(f) 2.3 mM eqvaterite 94%  calcite 4% halite 2%

Seawater based synthetic brine without NaCl (seawater+27.9 g/L CaCl₂)was treated with 25% wt Na₂CO₃, which resulted in 92% vaterite contentin the precipitated material. The initial ratio of Ca:Mg([Ca²⁺]_(i):[Mg²⁺]_(i)) was about 4:1. Table 20 shows the concentrationsof the initial and final ions in the solution.

TABLE 20 Synthetic brine (seawater) [Ca²⁺]_(i) 0.20M [Mg²⁺]_(i) 0.05M[NaCl]_(i) 0.47M [Ca²⁺]_(f) 0.10M [Mg²⁺]_(f) 0.05M Alk_(f) — vaterite92%  calcite 5% halite 3%

Deionized water based synthetic brine (Deionized water+29.4 g/L CaCl₂)was treated with 25% wt Na₂CO₃, which resulted in 90% vaterite contentin the precipitated material. The absence of magnesium did not seem tohave an effect on the precipitation of vaterite. Table 21 shows theconcentrations of the initial and final ions in the solution.

TABLE 21 Synthetic brine (deionized water) [Ca²⁺]_(i) 0.20M [Mg²⁺]_(i) —[NaCl]_(i) — [Ca²⁺]_(f) 0.10M [Mg²⁺]_(f) — vaterite 90%  calcite 5%amorphous 5%

Example 15 Brines with Carbonates

In this study, an effect of a ratio of calcium with the base in theformation of the carbonate precipitate is studied. Variousconcentrations of brine containing 0.2 M Ca²⁺ were treated withdifferent concentrations of sodium carbonate.

Table 22 illustrates the formation of vaterite compositions fromsynthetic brine (tap water+29.4 g/L CaCl₂) (0M NaCl+0.2M Ca²⁺) withcalcium:base stiochiometric ratio of 1:1.

TABLE 22 Liquid Na₂CO₃ CaCl₂ residence flow rate flow rate Yield Ca²⁺_(f) Alk_(f) PSA [Na₂CO₃] time (mL/min) (mL/min) (g/L) (mM) (mM eq) (μm)XRD Sample 1 0.25M 10 min 44.4 55.6 — 0.10 25.63 Median 26.81 94.6%vaterite Mean 27.25 5.4% calcite Sample 2 0.25M 10 min 44.4 55.6 ~10.281.36 11.40 Median 27.39 90% vaterite Mean 28.01 10% calcite Sample 30.25M 10 min 44.4 55.6 ~10.14 7.45 Median 31.28 95.2% vaterite Mean32.17 3.5% calcite Sample 4 0.25M 10 min 28.6 71.4 ~13.52 14.89 Median24.35 96.9% vaterite Mean 23.52 3.1% calcite

Table 23 illustrates the formation of vaterite compositions fromsynthetic brine (tap water+29.4 g/L CaCl₂) (0M NaC+0.2M Ca²⁺) withcalcium:base stiochiometric ratio of 1.5:1.

TABLE 23 Liquid Na₂CO₃ CaCl₂ residence flow rate flow rate Yield Ca²⁺_(f) Alk_(f) PSA [Na₂CO₃] time (mL/min) (mL/min) (g/L) (mM) (mM eq) (μm)XRD Sample 1  0.5M 20 min  10.5 39.5 — 19.96 4.40 Median 21.49 85.9%vaterite Mean 22.36 14.1% calcite Sample 2 0.25M 5 min 69.6 130.4 ~8.844.40 Median 17.71 93.1% vaterite Mean 18.50 6.9% calcite Sample 3 0.25M5 min 69.6 130.4 ~8.92 33.92 4.03 Median 18.00 85.9% vaterite Mean 18.8414.1% calcite Sample 4 0.25M 5 min 69.6 130.4 ~9.07 32.92 4.67 Median17.65 91.9% vaterite Mean 18.44 8.1% calcite

Table 24 illustrates the formation of vaterite compositions fromsynthetic brine (tap water+29.4 g/L CaCl₂) (0M NaCl+0.2M Ca²⁺) withcalcium:base stiochiometric ratio of 2:1.

TABLE 24 Liquid Na₂CO₃ CaCl₂ residence flow rate flow rate Yield Ca²⁺_(f) Alk_(f) PSA [Na₂CO₃] time (mL/min) (mL/min) (g/L) (mM) (mM eq) (μm)XRD Sample 1 0.25M 5 min 57.1 142.9 — 78.22 3.70 Median 11.06 96.8%vaterite Mean 11.53 3.2% calcite Sample 2 0.25M 5 min 57.1 142.9 ~7.2161.72 1.51 Median 14.03 94.6% vaterite Mean 14.60 5.4% calcite Sample 30.25M 5 min 57.1 142.9 ~7.29 63.40 4.01 Median 12.07 91.6% vaterite Mean12.55 8.4% calcite

Table 25 illustrates the formation of vaterite composition fromsynthetic brine (tap water+29.4 g/L CaCl₂) (0.6M NaCl+0.2M Ca²⁺) withcalcium:base stiochiometric ratio of 1:1.

TABLE 25 Liquid Na₂CO₃ CaCl₂ residence flow rate flow rate Yield Ca²⁺_(f) Alk_(f) [Na₂CO₃] time (mL/min) (mL/min) (g/L) (mmol/L) (mmol/Kg)XRD 0.25M 20 min 22.2 27.8 ~9.78 0.14 19.51 95.5% vaterite 4.5% calcite

Table 26 illustrates the formation of vaterite composition fromsynthetic brine (tap water+29.4 g/L CaCl₂+35.06 g/L NaCl) (0.6MNaCl+0.2M Ca²⁺) with calcium:base stiochiometric ratio of 1.5:1.

TABLE 26 Liquid Na₂CO₃ CaCl₂ residence flow rate flow rate Yield Ca²⁺_(f) Alk_(f) [Na₂CO₃] time (mL/min) (mL/min) (g/L) (mmol/L) (mmol/Kg)XRD Sample 1 0.25M 10 min 34.8 65.2 ~6.89 52.26 3.84 93.7% vaterite 6.2%calcite Sample 2  0.5M 20 min 10.5 39.5 ~11.24 3.66 95.2% vaterite 4.8%calcite

Table 27 illustrates the formation of vaterite composition fromsynthetic brine (tap water+29.4 g/L CaCl₂+35.06 g/L NaCl) (0.6MNaCl+0.2M Ca²⁺) with calcium:base stiochiometric ratio of 2:1.

TABLE 27 Liquid Na₂CO₃ CaCl₂ residence flow rate flow rate Yield Ca²⁺_(f) Alk_(f) [Na₂CO₃] time (mL/min) (mL/min) (g/L) (mmol/L) (mmol/Kg)XRD 0.5M 5 min 33.3 166.7 ~8.80 68.02 4.44 95.5% vaterite 4.5% calcite

Table 28 illustrates the formation of vaterite composition fromsynthetic brine (2.1M NaCl+0.2M Ca²⁺) with calcium:base stiochiometricratio of 1:1.

TABLE 28 Liquid Na₂CO₃ CaCl₂ residence flow rate flow rate Yield Ca²⁺_(f) Alk_(f) [Na₂CO₃] time (mL/min) (mL/min) (g/L) (mmol/L) (mmol/Kg)XRD 0.5M 5 min 57.1 142.9 ~13.45 0.20 24.09 81.9% vaterite 14.8% calcite3.3% halite

Table 29 illustrates the formation of vaterite composition fromsynthetic brine (2.1M NaCl+0.2M Ca²⁺) with calcium:base stiochiometricratio of 1.5:1.

TABLE 29 Liquid Na₂CO₃ CaCl₂ residence flow rate flow rate Yield Ca²⁺_(f) Alk_(f) [Na₂CO₃] time (mL/min) (mL/min) (g/L) (mmol/L) (mmol/Kg)XRD 0.25M 5 min 69.6 130.4 ~9.63 24.58 4 95.5% vaterite 4.5% calcite

Table 30 illustrates the formation of vaterite composition fromsynthetic brine (tap water+29.4 g/L CaCl₂+122.72 g/L NaCl) (2.1MNaCl+0.2M Ca²⁺) with calcium:base stiochiometric ratio of 2:1.

TABLE 30 Liquid Na₂CO₃ CaCl₂ residence flow rate flow rate Yield Ca²⁺_(f) Alk_(f) [Na₂CO₃] time (mL/min) (mL/min) (g/L) (mmol/L) (mmol/Kg)XRD Sample 1 0.25M 20 min 14.3 35.7 ~8.03 48.02 4.12 76.3% vaterite22.7% calcite 1% halite Sample 2  0.5M 10 min 16.7 83.3 ~8.95 60.06 3.6092.8% vaterite 5% calcite 2.2% halite

Example 16 Stability of Vaterite Compositions

Vaterite composition made from seawater+CaCl₂ dihydrate+NaCl+25% wtNa₂CO₃ was found to be stable over a period of 4 days (as shown in Table31 and FIG. 29) in the mother supernate.

TABLE 31 Day 1 Day 3 Day 4 Vaterite 69% Vaterite 65% Vaterite 65%Calcite 29% Calcite 30% Calcite 31% Halite 2% Halite 4% Halite 4%

Example 17 Stability of Vaterite Compositions

In this study, an effect of a ratio of calcium with the base on thestability of the vaterite composition was studied. Vaterite compositionmade from tap water+CaCl₂ dihydrate+0.25M Na₂CO₃ (Ca:base stiochiometricratio of 1:1) was found to be stable over a period of 2 days (as shownin FIG. 30 (FIG. 30A for solid obtained after dewatering but before ovendrying; FIG. 30B for solid obtained after dewatering and after ovendrying; FIG. 30C for slurry as is from precipitation of the compositionafter day 1; and FIG. 30D for slurry as is from precipitation of thecomposition after day 2)) in the mother supernate.

Vaterite composition made from tap water+CaCl₂ dihydrate+0.25M Na₂CO₃(Ca:base stiochiometric ratio of 1.5:1) was found to show sometransformation to calcite over a period of 2 days (as shown in FIG. 31(FIG. 31A for solid obtained after dewatering but before oven drying;FIG. 31B for solid obtained after dewatering and after oven drying; FIG.31C for slurry as is from precipitation of the composition after day 1;and FIG. 31D for slurry as is from precipitation of the compositionafter day 2)) in the mother supernate.

Vaterite composition made from tap water+CaCl₂ dihydrate+0.25M Na₂CO₃(Ca:base stiochiometric ratio of 2:1) was found to show almost completetransformation to calcite over a period of 2 days (as shown in FIG. 32(FIG. 32A for solid obtained after dewatering but before oven drying;FIG. 32B for solid obtained after dewatering and after oven drying; FIG.32C for slurry as is from precipitation of the composition after day 1;and FIG. 32D for slurry as is from precipitation of the compositionafter day 2)) in the mother supernate.

Example 18 Stability of Vaterite Compositions

Vaterite composition made from deionized water+CaCl₂ dihydrate+25% wtNa₂CO₃ was found to show some transformation to calcite overnight. Theprecipitate filtered and oven dried on day 1 contained 87% vaterite, 6%calcite, and 8% ACC. Vaterite showed no agglomeration on day 1. Theprecipitate that settled overnight was filtered and oven dried the nextday. The composition contained 52% vaterite and 48% calcite.

Example 19 Stability of Vaterite Compositions

Vaterite composition made from seawater based brine was left in themother supernate for 7 days. After 7 days, the precipitate showed 87.4%vaterite, 7% calcite, and 5.6% aragonite. Vaterite composition made fromseawater based brine was dewatered and was left into process water for 7days. The precipitate transformed into calcite over 7 days.

Example 20 Synthesis of Self-Cementing Precipitate

This experiment is related to the synthesis and analysis of theself-cementing calcium carbonate precipitate. The self-cementing calciumcarbonate precipitate was prepared by the following conditions:

-   Alkalinity: 0.5 M NaOH (520 mmol/Kg titrated)-   Flue Gas: Average of 145 acfm at 9.0-9.3% CO₂ (from propane)-   Brine: 0.18M Ca; 0.048 M Mg; pH 7.6 (Seawater based brine)-   Flowrates: 4.6 GPM Base, 9.0 GPM Brine-   Precipitation Tank Residence Time: ˜5 minutes    The measured values from the run were as follows:-   Base Utilization: 1.2 (CEMS/Venturi calculated)-   Absorber Outlet BiC/Carb: 1.03 (titrated as >100% Na₂CO₃)-   Average % CO₂ absorbed: 36% (5.8 moles/min)-   pH absorber: 11.1-11.5-   pH precipitation tank: 7.6-8.5-   Supernate Ca, Mg=0.034, 0.027 M

The reactants after mixing under above specified conditions resulted inthe formation of a precipitate. The precipitated slurry was analyzed forthe particle size and for polymorph content. The particle size of theprecipitate was analyzed using laser scattering particle sizedistribution analyzer and was found to be 24 microns. FIG. 33illustrates the SEM image of the precipitate showing the clusters ofvaterite. The XRD pattern of the precipitate showed 82% vaterite and 18%calcite. The coulometry showed carbon to be 11.1% and CO₃ to be 40.8%.The chloride was found to be 0%. Following was the elemental analysis ofthe precipitated slurry.

Element Concentration Na₂O 0.2105% MgO 0.2793% Al₂O₃ 0.0381% SiO₂0.1489% P₂O₅ 39.9 ppm SO₃ 0.16724%  Cl 0.5246% K₂O  0.01% CaO  54.46%TiO₂  0.00% Cr 0.00 ppm MnO [0.00029]%   Fe₂O₃ 0.00494%  Zn  0.8 ppm As0.00 ppm Se 0.00 ppm Br [0.000124]%    Rb [0.30] ppm   Sr 1099.8 ppm  Y[0.30] ppm   Zr  5.8 ppm

The precipitated slurry after dewatering and washing with fresh waterresulted in a material that set over a few days. This material was ovendried at 40° C. which after drying showed 63% vaterite, 11% calcite, and26% aragonite.

The material was then placed in a moist 60° C. curing chamber with 50%humidity which resulted in the cemented material with 73% aragonite, 15%calcite, 10% vaterite, and 2% halite. It is contemplated that the heatand the moisture transformed the vaterite to aragonite to result incementation.

Example 21 Synthesis of Cement Material

The vaterite compositions were precipitated, dewatered and dried basedon the protocols described above. The composition obtained was dried toform a flowable and dry powder (<5% RH (relative humidity)). Thecomposition was mixed at 0.3 liquid to powder ratio with water. It iscontemplated that lower water inclusion provides higher strength of thematerial formed. The composition could be reconstituted to form paste,which were then molded and poured to cure and form a hardenedcementitious mass.

The compositions were blended with deionized water (sample 1), tap water(sample 2), as well as a mix of ionic water composed of 5 ppm iron and0.1M NaHCO₃ (sample 3). The sample 1 showed 89.8% vaterite, 3.4%aragonite and 6.8% calcite before blending with DI water. The sample 1showed 4% vaterite, 72.8% aragonite and 3.5% calcite after blending withDI water and 28 days of curing. The sample 2 showed 89.8% vaterite, 3.4%aragonite and 6.8% calcite before blending with tap mix. The sample 2showed 2.7% vaterite, 91.3% aragonite, 5.3% calcite, and 0.7% haliteafter blending with tap mix and 28 days of curing. The sample 3 showed89.8% vaterite, 3.4% aragonite and 6.8% calcite before blending withionic mix. The sample 3 showed 3.4% vaterite, 76.6% aragonite, and 3.8%calcite after blending with ionic mix and 28 days of curing. Strengthresults at 7, 14, 28 and 56 days are corresponding to Table 32 below.

TABLE 32 7 day 14 day 28 day 56 day (psi) (psi) (psi) (psi) Sample 1 DIMix, DI Bath 3200 3590 3870 4200 Sample 2 Tap Mix, Tap Bath 2860 40904420 3860 Sample 3 Ionic Mix, Tap Bath 3330 4160 4530 4340

Example 22 Performance Tests

The composition containing 20% SCM composition of the invention(prepared in accordance with example 8 described above and containing83% vaterite and 17% calcite) and 80% OPC was subjected to variousperformance tests based on ASTM C1157. Table 33 summarizes the tests andthe results. The performance test results, of 20% SCM of the inventionmixed with 80% OPC, were found to be comparable to 100% OPC.

TABLE 33 20% SCM of the 100% Test invention + 80% OPC OPC Blainefineness (ASTM C 204) 599 m²/Kg 456 m²/Kg Air content of hydraulic 21.7%  23.1% cement mortar (ASTM C 185) Heat of hydration (isothermal88% of OPC calorimetry) at 3-day Consistency (ASTM C 187) and 84 min 146min setting time (ASTM C 191) Autoclave expansion (ASTM C 0.209% 0.003%151) Compression strength (ASTM C 98% of OPC at 7-day 109) Expansion(ASTM C 1038) 0.004% at 2-week 0.006% Drying shrinkage (ASTM C 0.076% at2-week 0.066% 596) Sulfate expansion (ASTM C 0.014% at 2-week 0.011%1012)

The comparison of the performance test results of 20% SCM of theinvention and 80% OPC with the GU specifications were also found to becomparable as illustrated in Table 34.

TABLE 34 20% SCM of the Property Method GU Specification invention + 80%OPC Flow^((a)) ASTM C1437 110 +/− 5% N/A Vicat set time, min ASTM C19145-240  84 1 day compression, psi ASTM C109 N/A 1800^((a)) 3 dayscompression, psi ASTM C109 1890 3330^((a)) 7 days compression, psi ASTMC109 2900 4160^((a)) Mortar bar expansion, % max ASTM C1038 0.02 @ 14days 0.004%  Air content of mortar, % ASTM C185 Report Value 21.7%Fineness: Blaine, m²/kg ASTM C204 Report Value   599.8 Autoclaveexpansion, max % ASTM C151     0.80 0.21% ^((a))20% SCM of the inventionand reference OPC material mixes at constant water/cement ratio of 0.49for direct comparison

Example 23 Blended Compositions

Various compositions of the invention were blended with Portland cementand other materials to form aggregates and mortar cubes with calciumcarbonate and magnesium carbonate aggregates. Table 35 shows some of theblended compositions.

TABLE 35 Fly Fly compo- Portland CTS ash ash Potassium Sodium Whitesition Cement Cement C F Silicate Silicate Cement 50 50 50 50 50 50 5050 50 50 50 50 70 30 60 40 40 60 30 70 50 25 25 50 25 25 60 20 20 60 4050 40 10 60 40 80 10 10 80 10 10 60 20 20 60 20 20

The compositions illustrated in Table 35 were a blended mix ofindividual compositions containing different amounts of vaterite. Someof the individual compositions are illustrated in Table 36.

TABLE 36 Process to prepare the Vaterite: Composition compositionVaterite Calcite Halite Calcite Aragonite 1 0.2M CaCl₂ 100 0.0 0.5M NaOH2.2 GPM NaOH, 6.2 GPM Brine Edited conditions to achieve 11.3 pH inabsorber and <7.7 in ppt stage 2 0.5M NaOH 6.7 5.1 1.3 88.2 0.195 Ca,0.048 Mg (seawater brine) 9.4 GPM brine, 5.0 GPM base Startup conditions= brine filled tank 3 93.4 6.6 14.2 4 Testing of Ca/Mg = 4:1 83.8 16.25.2 with Ca/CO₃ = 1.5, 2.5, 3.5 and 4.5 Brine made with HD98 Low MgCaCl₂ liquid Stock Absorber flow = 4.7 GPM; Brine Flow = 8.6, 14.4, 20,29 GPM Ca = 0.19M; Mg = 0.045M 5 14.3 85.7 0.2 6 50 50 1.0 7 35 65 0.5 8Production run for 95.3 4.7 repeat (standard vaterite conditions)Ca/CO₃= 1.5 Ca/Mg = 4 9 92.6 2.8 33.1 10 96 4 24.0 11 96 4 24.0 12Inline/Static Mixer 61.3 5.9 10.4 31.8 (small unit) 13 275 gal ofsynbrine 21.1 63.9 4.4 0.3 10.6 [27.9 g/L CaCl₂ + Seawater], 16.5 kg of50% NaOH, ~2 scfm CO₂ (no air), maintained pH between 7.8-8.5, final pH= 8.1. Material was spray dried directly after settling. 14 275 gal ofsynbrine 22.2 71.2 6.5 0.3 [27.9 g/L CaCl₂ + Seawater], 16.5 kg of 50%NaOH, ~2 scfm CO₂ (no air), maintained pH between 7.8-8.5, final pH =7.98. Material was spray dried directly after settling. 15 300 galVaterite 4.8 94.7 0.5 0.1 Precipitation 300 gal of synbrine [27.9 g/LCaCl₂ + Seawater], 18.0 kg of 50% NaOH, ~3 scfm CO₂ (no air), maintainedpH between 7.8-8.5, final pH = 7.98. Material was spray dried directlyafter vacuum filtering. 16 300 gal of synbrine 2.8 92.8 4.4 0.0 [27.9g/L CaCl₂ + Seawater], 18.0 kg of 50% NaOH, ~3 scfm CO₂ (no air),maintained pH between 7.8-8.5, final pH = 7.98. Material was spray drieddirectly after vacuum filtering. 17 300 gal of synbrine 19.8 76.5 3.70.3 [27.9 g/L CaCl₂ + Seawater], 18.0 kg of 50% NaOH, ~3.5 scfm CO₂ (noair), maintained pH between 7.8-8.5, final pH = 7.49. Material was spraydried directly after vacuum filtering with a rinse of fresh water. 18300 gal of 1 day old 70 30 2.3 synbrine [27.9 g/L CaCl₂ + Seawater],18.0 kg of 50% NaOH, ~3.5 scfm CO₂ (no air), maintained pH between7.8-8.5, final pH = 8.04. Material was spray dried after being re-slurried and vacuum filtered twice. 19 70 30 2.3 20 300 gal of synbrine75.2 24.8 3.0 [27.9 g/L CaCl₂ + Seawater], 18.0 kg of 50% NaOH, ~3.5scfm CO₂ (no air), maintained pH between 7.8-8.5, final pH = 7.8.Material was spray dried after being re- slurried and vacuum filteredtwice. 21 75.2 24.8 3.0 22 300 gal of synbrine 70.2 29.8 2.4 [27.9 g/LCaCl₂ + Seawater], 18.0 kg of 50% NaOH, ~3.5 scfm CO₂ (no air),maintained pH between 7.8-8.5, final pH = 7.8. Material was spray driedafter being re- slurried and vacuum filtered twice. 23 90.4 4.3 5.3 21.024 89 3 8.1 29.7 25 79.7 18 2.3 4.4 26 78.1 19.7 2.3 4.0 27 58.8 40.50.7 1.5 28 76.1 19.9 4 3.8 29 36.9 60.3 2.9 0.6 30 11.5 87 1.5 0.1 3149.3 47.4 3.3 1.0 32 65.5 31.8 2.7 2.1 33 82.4 14.4 3.1 5.7 34 6.6 91.61.8 0.1 35 50.2 47.7 2.2 1.1 36 26.1 70.9 3 0.4 37 16.7 81 2.3 0.2

The compositions 1-12 of Table 36 were also used to prepare 100% selfcement aggregate cube samples. The compositions after precipitation weredewatered and the dewatered material was placed in baby ice cube molds.

Example 24 Synthesis of Vaterite Compositions

Materials and Instruments:

X-ray diffraction: Rigaku miniflex, 30 KV, 15 mA, 2-90°2θ, 2°2θ per min,0.01°2θ per step, Rietveld refinement with Jade 9. SEM: Hitachi TM-1000used to image minerals dried at less than 50° C., Au coating.Compression tested on ELE load frame (ELE International) with MTS (MTSSystems Corp.) compression cell. Laser particle size distribution:Horiba particle size unit. Nitrogen gas surface analysis: micromiriticsmodel.

The XRD pattern of the vaterite composition showed 83.3% vaterite, 9.2%calcite, 4.7% gypsum, and 2.8% halite before mixing with water and theparticle size before mixing with water was about 6 microns.

The vaterite composition of the invention was mixed with DI water at aliquid:powder ratio of 0.3. The slurry was poured into molds and wascured for 3 days at 85% RH (relative humidity). After removing frommolds, the product was allowed to cure in DI water for another 4 days,11 days, and 25 days. Resulting samples were tested for compressivestrength, x-ray diffraction, and FTIR.

The XRD pattern after 28 days, showed 91.4% aragonite, 2.8% vaterite,2.5% calcite, and 3.3% gypsum. The compressive strength of thecomposition after curing for 7 days, 14 days, and 28 days, isillustrated in FIG. 34.

1. A non-naturally occurring self-cementing composition, consistingessentially of carbonate precipitate in water comprising: at least 1%w/w vaterite, wherein the composition after setting and hardening inwater has a compressive strength of at least 14 MPa and wherein thecomposition comprises a carbon isotopic fractionation value (δ¹³C) ofbetween −12‰ to −25‰.
 2. The composition of claim 1, wherein thecomposition has a compressive strength in a range of 20-40 MPa.
 3. Thecomposition of claim 1, wherein the vaterite is in a range of 47% w/w to99% w/w.
 4. The composition of claim 1, wherein the composition furthercomprises ACC in a range of 1% w/w to 99% w/w.
 5. The composition ofclaim 1, further comprising a polymorph selected from the groupconsisting of amorphous calcium carbonate, aragonite, calcite, ikaite, aprecursor phase of vaterite, a precursor phase of aragonite, anintermediary phase that is less stable than calcite, polymorphic formsin between these polymorphs, and combination thereof.
 6. The compositionof claim 1, further comprising a polymorph selected from the groupconsisting of aragonite, calcite, ikaite, and combination thereof,wherein the aragonite, calcite, ikaite, or combination thereof areindependently in a range of between 1% w/w to 80% w/w.
 7. Thecomposition of claim 1, further comprising strontium (Sr) in an amountof 1-50,000 parts per million (ppm).
 8. The composition of claim 1,wherein the composition is a particulate composition with an averageparticle size of 0.1-100 microns.
 9. The composition of claim 1, furthercomprising nitrogen oxide, sulfur oxide, mercury, metal, derivative ofany of nitrogen oxide, sulfur oxide, mercury, and/or metal, orcombination thereof.
 10. The composition of claim 1, wherein thecomposition has a zeta potential of between −25 to 45 mV.